Quite confusing!

Algebra Level 1

Evaluate

x 2 x + 1 , \frac{\sqrt{x^2}}{|x|} + 1,

where x x is a non-zero real number.

2 1 0 and 2 0

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117 solutions

Karthik Sharma
Aug 31, 2014

x 2 = x \sqrt{x^2} = |x| , so x 2 x + 1 = 1 + 1 = 2 \frac{\sqrt{x^2}}{|x|} + 1 = 1 + 1 = 2

The common misconception is that x 2 \sqrt{x^2} can be a negative number, but the only time square root returns a negative is if you're using it to solve an equation.

For instance, we say 100 = 10 \sqrt{100} = 10 , but if we had the equation x 2 = 100 x^2 = 100 , then x = ± 10 x = \pm 10 .

Root of one number has always has two solutions i.e -ve and +ve. so even if x*x results in positive and after that root of that number results in two intezers i.e +ve and -ve and so it results in two answers one is 2 and the other is 0.

praveen botcha - 6 years, 8 months ago

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But in this case, it is not just the square root of a number. It is the square root of the square of a number. So the resultant value after the square has to be positive,

Rahul Pal - 6 years, 7 months ago

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why is tht?

Rimanshu Keni - 6 years, 6 months ago

square root of any number can be both positive and negative. sqrt(3^2) =sqrt(9)=+3,-3

Ahmad Sazidy - 5 years, 9 months ago

But a square root is always a positive and negative solution

Olivia Seabolt - 6 years ago

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@Olivia Seabolt No, I believe that it only has two solutions when you are the one applying the square root. For example, if x^2 = 4, then x = ±2. However, if the given equation already has a square root in it, for example, sqrt(4) = x, then x must equal 2.

This is because in this particular equation, the square root is given as positive. You would never see an equation such as, a ± sqrt(b) = c, where c only has one solution. However, if you had a + b^2 = c, then b = ±sqrt(c - a).

If you had a given, a = 2, you would not randomly change it to a = ±2, if you get what I'm saying.

James Leung - 5 years, 7 months ago

@Olivia Seabolt you are right in a way because what ever you square will always be a different numba unless you are squarin it by one and it self. And i also had my school prom last nite which went really well.

Samuel Creed - 4 years, 11 months ago

if a^2=x^2 then a=+x or -x but Sqrt(x^2)=|x| always

Hirosh Thomas T T - 6 years, 4 months ago

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Why is that ?

Gaurav Yadav - 6 years ago

By convention the radical symbol returns the positive root.

Aaron S - 6 years, 6 months ago

But by definition, sqrt(x) is the inverse of the square of x,and only the principal root of a positive number is to be considered. In case you want to refer: http://mathworld.wolfram.com/SquareRoot.html

Ankit Singh - 6 years ago

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Actually it should be stated in the problem clearly...

Gaurav Yadav - 6 years ago

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@Gaurav Yadav It already is. Who uses the symbol to mean both roots?

Whitney Clark - 5 years, 1 month ago

x \sqrt{x} is only the inverse of x 2 x^2 on the interval [ 0 , ) [0, \infty) .

Krish Shah - 1 year, 1 month ago

"Where x is a non zero real number." Even if x could be zero, the value of (sqrt x^2)/abs x would be indeterminate.

Addison McKenzie - 5 years, 10 months ago

(2,0) i think correct answer if i am wrong plz tell correct answer

Ch Ali - 6 years, 9 months ago

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square root of x^2 is x/x=1+1=2

Ako Ni - 6 years, 9 months ago

I think u are right

Istiak Ahmed - 5 years, 8 months ago

The answer is only 2 2 .

By definition, x 2 = x \sqrt { { x }^{ 2 } } =\left| x \right| where x x is a real number.

x 2 = x = x \sqrt { { x }^{ 2 } } =\left| x \right| =x , if x 0 x\ge 0 .

x 2 = x = x \sqrt { { x }^{ 2 } } =\left| x \right| =-x , if x < 0 x<0 .

Kenneth Choo - 4 years, 11 months ago

I think the Only Answer is 2.....; even If x is -ve, x^2 is +ve. and then comes square root. so it is always 1+1 = 2

Jino Sebastian - 6 years, 9 months ago

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the square root of any positive real number has two solutions, one positive and one negative. Whether x is positive or negative is irrelevant as x^2 must be positive and thus its root will have 2 solutions, x and -x, leading to the two solutions 2 and 0

Doug Neal - 6 years, 8 months ago

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@Doug Neal The "square root" symbol as shown in the problem is the "positive square root" of the number inside, so the answer would always be positive.

Christopher Audino - 6 years, 8 months ago

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@Christopher Audino tell me man where it is mentioned "square root" is the "positive square root" .

Rachit Sharma - 6 years, 4 months ago

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@Rachit Sharma The fact that the radical operator always returns the positive root is a definition. Otherwise, it would not be able to specify a well-defined function. This comes from the study of branch cuts of multivalued functions in the complex plane (a more advanced topic), where you often are forced to pick a particular branch.

Andrew Droll - 5 years, 11 months ago

@Rachit Sharma "where x is a non zero real number." --> non-zero real number means start from +1.

Garvin Goei - 6 years, 4 months ago

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@Garvin Goei Non Zero Real Number only rules out the possibility of Infinity being the right answer, It does not indicate whether the SQ Root is Positive or Negative.

Karan Babar - 6 years, 2 months ago

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@Karan Babar Actually, since the term evaluates to some form of 0/0, that is not infinity, but is truly undefined.

Timothy Lin - 5 years, 10 months ago

@Doug Neal Unfortunately you are wrong on this one. The root of a number is defined to always be positive. You only consider the negative solution if it is you that makes the active decision to root a number. Since in this question the root sign does not have a +/- in front, only the positive solution is to be considered.

John Armstrong - 6 years, 8 months ago

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@John Armstrong True story bro.

Emmanuel Rivera - 6 years, 7 months ago

@John Armstrong So is a root number truly an absolute value by definition? conventional wisdom would seem to be that it could be negative or positive. ..ohhh I think I got it, you meant to say the square of a number is always positive. QEF

Tyler Mills - 6 years, 5 months ago

@Doug Neal right i think whats going on here is that the radical can return two results like the quadratic equations do but one of the roots is extraneous and will not satisfy the requirements - similar to when you solve an algebra problem and lets say the quadratic yields -3 and 8 for x, if its a length ,mass or quantity type problem we would reject -3 out of hand as a valid solution - it is extraneous because you can't have answers like "the board is -3 Meters long"

William Miller - 5 years, 10 months ago

from Basic algebra, the square root sign just always means the positive or principal square root.... this implies that the answer to problem is ONLY 2 and not 0 & 2.

Cyndmark Penaso - 6 years, 7 months ago

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why is that? i didn't understnad

Itay Oron - 1 year, 2 months ago

why is that only?

Puru Chevilear - 5 years, 7 months ago

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Because, always, both, root of x and mod x are positive.

Dorina Popescu - 5 years, 3 months ago

It's not that it "only returns a negative number when you are solving an equation." What people think of as sqrt(x) is a map from the positive reals to the positive reals. When you are solving an equation, though, e.g., x^2 = 9, you take the square root of both sides, getting sqrt(x^2) = sqrt(5), which gives |x| = 3, which gives x = -3 and x = 3. It's the absolute value equation that yields two values, not the square root.

According to the definition of the conventional square root over the reals, negatives are not in the range of the function at all. If they were, more than one f(x) would exist for every x and it wouldn't be a function.

Sean Conover - 5 years, 2 months ago

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correct! That |x|=3 step is what most people never come to know in school :)

Somesh Singh - 4 years, 5 months ago

Kartik Sharma is correct. The square root function is a mathematical function that will always give positive root. Only when applied in an equation (where the purpose is to find which values could lead to such a square) will both values (positive and negative) become solutions

Aditya Ishwar - 5 years, 1 month ago

The square root function always returns positive values .

Saran Balachandar - 4 years, 8 months ago

Correction: "the only time square root returns a negative is if you're using it to solve an equation."

The square root forever returns the principal root, whether or not in a quadratic polynomial.

The +- sign we append in front of it does NOT belong to the square root itself; it is the sign of the root of the polynomial.

Somesh Singh - 4 years, 5 months ago

For any real number x x not equal to 0 0 , there are two distinct complex numbers whose squares are equal to x x .

However, this does not mean that x \sqrt{x} has two values. By convention, the square root function is defined such that x \sqrt{x} is equal to the unique positive real number whose square is x x , whenever x x is a positive real number. Also, 0 = 0 \sqrt{0} = 0 . The value of x \sqrt{x} is not defined when x < 0 x < 0 (the domain of the function is the nonnegative real numbers).

In fact, this definition is precisely why the solutions to x 2 = y x^2 = y , say, are denoted x = ± y x = \pm \sqrt{y} (when y y is a positive real number). Here, y \sqrt{y} is defined to be the unique positive root of y y . Thus, to list all solutions to the equation, we actually have two possibilities: x = y x = \sqrt{y} and x = y x = -\sqrt{y} . We write x = ± y x = \pm\sqrt{y} as shorthand for these two possibilities. This notation does not indicate that y \sqrt{y} has two values (the opposite, actually).

In this question, x 2 x^2 is guaranteed to be a positive real number, because x x is a non-zero real number. x 2 \sqrt{x^2} is the unique positive number which squares to x 2 x^2 - in other words, x 2 \sqrt{x^2} is equal to x |x| (uniquely).

So the expression should be simplified to

x 2 x + 1 = x x + 1 = 1 + 1 = 2 \frac{\sqrt{x^2}}{|x|} + 1 = \frac{|x|}{|x|} + 1 = 1 + 1 = 2

2 2 is the unique answer to this problem.

N.B. It is only true that x 2 = x \sqrt{x^2} = x when x 0 x\geq 0 . In general, x 2 = x \sqrt{x^2} = |x| for real x x , by definition. This definition is taken as a matter of convention in order to allow the definition of a square root function from R + R \mathbb{R}^+ \rightarrow \mathbb{R} at all (the value of a function must always be uniquely defined by its arguments).

N.B. #2 If x x is a real number, it is always the case that x 2 = x \sqrt{x^2} = |x| , by the standard definition of the square root function. If you ever take it to mean anything else (the negative real root of x 2 x^2 , say), then you are no longer using the standard definition of the square root function.

Andrew Droll - 4 years, 4 months ago

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Your answer dispels all my doubts. Very well written!

Krish Shah - 1 year, 1 month ago

the answer is 2!! hehehe :p i got it so easily. did anyone else?

Rachel Hicks - 6 years, 9 months ago

any +ve number

Harshita Sai - 6 years, 9 months ago

this is really simple guys. \frac { \sqrt { { x }^{ 2 } } }{ \left| x \right| } +1=?\ \sqrt { { x }^{ 2 } } =\left| x \right| \quad and\quad \frac { \left| x \right| }{ \left| x \right| } =1.\ Therefore\quad 1+1=2

\sqrt { { x }^{ 2 } } is ALWAYS POSTIVE. It will NEVER equal -1 like you all keep saying. Therefore, there is only one answer: 2.

Braxton Salyer - 6 years, 8 months ago

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The fact that there is an absolute value sign in the denominator changes everything, SquareRoot(x^2)=x it was stated that x is a non zero real number, meaning it could be any number as long as it's not 0. If x=-2, -2/|-2|, -2/2=-1 without the absolute value sign, the answer will always be 2, but in this case once the value of x is less than 0, the answer becomes 0. The problem should have stated x>0 which would make 2 that only correct answer.

Adi Avishalom - 6 years, 6 months ago

Fudge the formatting guide, x^2 * x^0.5 = x^1

Thomas Ward - 6 years, 7 months ago

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Wrong. x^2 * x^0.5 = x^2.5, because you're supposed to ADD the exponents.

Whitney Clark - 4 years, 11 months ago

x/ |x| =n^. so, n^+1 = 2...

arul arul - 6 years, 5 months ago

But what if x=i, an imaginary number, then ex: (i^2)\sqrt{2}=i? So there would be two possible answers? (0 and 2)

Stéphanie Loubier - 5 years, 5 months ago

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if x x equals, let us say 2 i 2i , then:

x 2 = ( 2 i ) 2 = 2 2 × i 2 = 4 × i 2 = 2 i \sqrt{x^2} = \sqrt{(2i)^2} = \sqrt{2^2 \times i^2}= \sqrt{4} \times \sqrt{i^2} = 2i

Also, 2 i = 2 i = 2 i |2i| = |2|i = 2i

So, x 2 / x + 1 = 2 i / 2 i + 1 = 2 \sqrt{x^2}/|x| + 1 = 2i/2i+1=2

Even if x x is a negative imaginary, like if x = 3 i x=-3i , then:

x 2 = 3 i 2 = 3 2 × i 2 = 9 × i 2 = 3 i \sqrt{x^2} = \sqrt{-3i^2} = \sqrt{-3^2} \times \sqrt{i^2} = \sqrt{9} \times \sqrt{i^2} = 3i

And 3 i = 3 i = 3 i |-3i| = |-3|i = 3i

So, x 2 / x + 1 = 3 i / 3 i + 1 = 2 \sqrt{x^2}/|x|+1 = 3i/3i+1 = 2

The answer is only 2 in every case, not 0.

Somesh Singh - 4 years, 5 months ago

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Perhaps, you should place pairs of parentheses in parts of your solution to indicate proper squaring as well as not violating the rule that a b = a b \sqrt{ab}=\sqrt{a}\sqrt{b} only when either/both of a a and b 0 b≥0 .

Krish Shah - 1 year, 1 month ago

It is stated in the problem that x x is a non-zero real number.

If x x is in the form b i bi where b b is a non-zero real number and i 2 = 1 { i }^{ 2 }=-1 , then ( b i ) 2 = b i \sqrt { { \left( bi \right) }^{ 2 } } =\left| b \right| i .

Kenneth Choo - 4 years, 11 months ago

why can sqrt(100) is not equal to -10????? (-10)^ is also equal to 100. why why why why why why why why why why why?????????????

Yash Mehan - 5 years, 4 months ago

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square root is a function. It can only return ONE output for every input.

By convention, we define that ONE output to be the positive root of 100, which is 10, not -10.

Somesh Singh - 4 years, 5 months ago

As we know that ±√x² = ±x . Then -x/x + 1 = 0 and +x/x + 1 = 2 . So answer is 0 and 2 . We don't know what type of number is it . And also no need to know the definite number type of its to solve the problem . x and x² both can be any any thing ,such as neg or pos integer . or a complex number or so forth type what we have already known . Txs

Artabin Apon - 5 years, 1 month ago

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Um, no, the square root function doesn't refer to two different numbers. There are two roots, but the function only refers to one of them.

Whitney Clark - 5 years, 1 month ago

the answer can be 2 or else 0 because root of x^2 is -x or x as usual and henceforth the modx will alwaysbe +ve so there should be no confusion now i think now it is quite easy.....

Akhilesh Srivastav - 6 years, 9 months ago

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And divide by zero my phone will blow up if I typed in 0

Juan De Los Santos - 6 years, 7 months ago

I think the Only Answer is 2.....; even If x is -ve, x^2 is +ve. and then comes square root. so it is always 1+1 = 2

Jino Sebastian - 6 years, 9 months ago

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The issue arises as... regardless of whether x is positive or negative, x^2 as you say will be +ve, however every positive number will always have two seperate roots (+ve and -ve). e.g.

Let x = 2:

x^2 = 4, but sqrt(4) can be = 2 or -2. this gives (2 or -2) / 2, which in turn is equal to 1 or -1.

Hence the correct answer should be 0 or 2.

Jamie McCabe - 6 years, 3 months ago

I think the Only Answer is 2.....; even If x is -ve, x^2 is +ve. and then comes square root. so it is always 1+1 = 2

Jino Sebastian - 6 years, 9 months ago

2... since its a non zero real number

Renmar Abania - 6 years, 9 months ago

so do i ch ali.

Sagnik Chanda - 6 years, 8 months ago

Right i think its a perfect answer for this solution but u should explain y it is equal root of x square is always x and absolute x is also x .

Shubham Gaikwad - 6 years ago

I disagree with u.What we are doing here is also equation solving. This problem has 2 solutions: 0 or 2.

Nithin Shaju - 5 years, 8 months ago

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This is not an equation. It's an expression.

By definition, x 2 = x \sqrt { { x }^{ 2 } } =\left| x \right| where x x is a real number.

Kenneth Choo - 4 years, 11 months ago

This question is told improperly. The square root of x squared is simplified to simply x. This makes it x over the absolute value of x. If x is negative then it would be -1, but if positive then it would be 1. So either the answers 0 or 2 would be correct.

Todd Koss - 5 years, 6 months ago

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By definition, x 2 = x \sqrt { { x }^{ 2 } } =\left| x \right| where x x is a real number.

Kenneth Choo - 4 years, 11 months ago

It is false because root of a number can be positive or negative

Diptangshu Panda - 5 years, 2 months ago

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square root of a number is always non-negative; it is the roots of a quadratic polynomial that can be both positive and negative.

Somesh Singh - 4 years, 5 months ago

No square root always returns positive values .

x 2 = x \sqrt { x^{ 2 } } =\quad \left| x \right|

Saran Balachandar - 4 years, 8 months ago

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You mean nonnegative values. Zero is the sqrt of zero.

Whitney Clark - 4 years, 8 months ago

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@Whitney Clark Yeah . Thanks for the correction. :)

Saran Balachandar - 4 years, 8 months ago

If there is an x, there is an equation

Ana Tofetti - 5 years ago

This is wrong. It's 0 and 2

Timothy Faerber - 5 years ago

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No it isn't. The sqrt symbol refers to the principal root ONLY.

Whitney Clark - 5 years ago

As a physicist, you math types are annoying. Your bizarre technicality doesn't exist in physics were every sqrt has two roots. It's actually fundamental in some derivations!

Troy Broderick - 5 years, 1 month ago

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It is defined that x 2 = x \sqrt { { x }^{ 2 } } =\left| x \right| , where x x is a real number. It's the principal square root or the square root function . You should look it up again. It's very important for you as a physicist.

Does A Square Root Have Two Values? | Brilliant Math and Science Wiki

Square root - Wikipedia, the free encyclopedia

Kenneth Choo - 4 years, 11 months ago

Actually, the idea of accepting only the principal root comes from the need to define "sqrt" as a function. As you might be aware of the fact that a function can be one to one, many to one, but never one to many; meaning it cannot return two outputs for a single input. That is precisely why mathematicians have defined the sqrt operator to return only the principal root!

Somesh Singh - 4 years, 5 months ago

But how are you supposed to refer to them individually?

Whitney Clark - 5 years, 1 month ago

the key is x is a non zero real number, so it can not be 0..

Karla Robiso - 6 years, 9 months ago

√x2/|x|+1=+1+1=2:-1+1=0

Diptangshu Panda - 5 years, 2 months ago

the confusion starts whether root of x^2 is positive or negative .....!!! it doesn't matter if it is positive or negative ..... it just matters that root of x^2 is always x .....!! for eg ; root of 16 may be 4 or -4 .... but root of 4^2 is always 4 and root of (-4)^2 is always -4 . so that implies the first part of equation being x/x which always equals 1 ... and final answer 2 .....!!

Rudra Sanjeev - 6 years, 9 months ago

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boss, ur not dividing x by x; ur dividing 'x' by mod(x)...so if x is a negative number,,,,then x/mod(x) would be -1 and eqn evaluates to 0!!! so in my opinion,,,the answer can be either 2 or 0.. :-)

Somesh Singh - 6 years, 9 months ago

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But it wouldn't accept two values i.e 2 & 0. :(

Keshav Gaur - 6 years, 9 months ago

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@Keshav Gaur yeah it wont accept...but its the publisher's fault isn't it...

Somesh Singh - 6 years, 9 months ago

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@Somesh Singh

  1. ( 4 ) 2 = 4 (\sqrt{-4})^2=-4
  2. ( 4 ) 2 4 \sqrt{(-4)^2}\neq-4
  3. ( 4 ) 2 = 4 \sqrt{(-4)^2}=4
Please note the difference.

Vicky Andrew - 6 years, 9 months ago

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@Vicky Andrew Example 2 is incorrect, lets rewrite that as ((-4)^2)^(1/2)=(-4)^(2/2)=(-4)^1= -4

Adi Avishalom - 6 years, 6 months ago

@Vicky Andrew Disagree with example 2. The square root can take a positive or negative value.

Stevaan Hall - 6 years, 9 months ago

@Vicky Andrew thnx sir!!!

Somesh Singh - 6 years, 9 months ago

@Vicky Andrew The square root of -4 is 2i, where i is the imaginary number of the square root of a negative number. Once that value, being 2i is squared, the value becomes -4. Simple answer: the answer is technically impossible. Side note, as stated in this response: (-n)^2 = n n -n^2 = -1 n*n where n is any number, positive or negative.

Tyler Schommer - 6 years, 9 months ago

@Vicky Andrew Just do a substitution and it's very clear that 2 and 0 is the correct answer here we substitute 4 for x:

x 2 x \frac {\sqrt{x^{2}}}{|x|} = 4 2 4 \frac {\sqrt{4^{2}}}{4} = 16 4 \frac {\sqrt{16}}{4} = + 4 4 \frac {+-4}{4} = 1 or -1

1+1 is 2 and -1+1 = 0.

See documentation here for square root calculation definition: http://en.wikipedia.org/wiki/Square_root http://mathworld.wolfram.com/SquareRoot.html

Alex Carter - 6 years, 8 months ago

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@Alex Carter your idea is right BUT take note, from basic algebra the square root sign just always denotes the positive or principal square root,,,,, this implies that only 2 is acceptable as the final answer. :)

Cyndmark Penaso - 6 years, 7 months ago

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@Cyndmark Penaso I'm sorry, I just don't agree that the symbol you're talking about "always" denotes positive or principal square roots. It is clearly an issue of convention and can easily mean both negative and positive values or just the positive value depending on the conventions you're working with.

However, I will agree with you that in this context the convention is rather clear (even though it is still implicit) about what the "expected" answer is. The reason why it is implicit is because you have to take into account that the question asked is for us to "evaluate" the problem, which implies there is supposed to be only one answer.

Nicholas Rees - 6 years, 6 months ago

@Alex Carter Because you wnat it!!!Common sense in this case exponencial before square root...

Márcio Nascimento - 6 years, 8 months ago

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@Márcio Nascimento The square root is an exponent too, it is just to the 1/2 power.

Adi Avishalom - 6 years, 6 months ago

@Alex Carter It is written "where x is a non zero real number" so we know that the root should be positive, not negative.

Garvin Goei - 6 years, 4 months ago

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@Garvin Goei I'm afraid that there are 2 things wrong with that statement:

  1. regardless of whether x is +ve or -ve, x^2 will be +ve, but the root of this positive number can always be +ve or -ve.

  2. Real numbers can be +ve or -ve. This only rules out the inclusion of imaginary numbers, i.e. x^2 cannot be -ve.

Jamie McCabe - 6 years, 3 months ago

@Somesh Singh no its your fault

vivek kushal - 6 years, 9 months ago

@Keshav Gaur Who said it cannot hv two values. Its an equation, can have any number of values!

Ushasi Dutta - 6 years, 9 months ago

square root of x^2 is not 'x' it is mod(x) hence the ans is 2 only not 0

vivek kushal - 6 years, 9 months ago

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@Vivek Kushal the square root of (-4)^2 is 4 according to you isn't it....but thats ridiculous.... the square root of (-4)^2 is -4 not 4 :) :) :)

Somesh Singh - 6 years, 9 months ago

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@Somesh Singh it shows how dumb r u....please go and learn some maths....by the way square root of (-4)^2 is 4 not -4...see wikipedia

vivek kushal - 6 years, 9 months ago

correct but root of (-4)^2 is also 4

vivek kushal - 6 years, 9 months ago

It is not true that sqrt(x^2) is always equal to x. In fact, if x < 0, then sqrt(x^2) = -x. What is true is that sqrt(x^2) = |x| for every real number x, which is the reason that the answer to this problem is 2 for all real x not equal to 0.

Andrew Droll - 5 years, 11 months ago

the answer is 0,2 because the square root has -,+ answers if its even.

Mohammad Taroumian - 6 years, 9 months ago

But |x| also equals to x and -x.

Pratiksha Sharma - 5 years, 8 months ago

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For all real numbers x x ,

x 2 = x = x \sqrt { { x }^{ 2 } } =\left| x \right| =x , if x 0 x\ge 0 ,

x 2 = x = x \sqrt { { x }^{ 2 } } =\left| x \right| =-x , if x < 0 x<0 .

Kenneth Choo - 4 years, 11 months ago

Not at all confusing or hard >>>
root x^2 = x / |x| + 1 x/x+1 1+1 2 ........ really simple question ... :)

Aasif Khan - 6 years, 9 months ago

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It's not that simple. there will be 2 answers if qn was x/|x| where x is non zero real no....

Jino Sebastian - 6 years, 9 months ago

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It's that simple.

By definition, x 2 = x \sqrt { { x }^{ 2 } } =\left| x \right| where x x is a real number.

Kenneth Choo - 4 years, 11 months ago

But that was not the question Jino. Aasif Khan is correct

Ken Roth - 6 years, 8 months ago
Stevaan Hall
Sep 13, 2014

This is the first question on brilliant where I don't agree with most of the solutions.

Disagree with this solution.

Answer is 2 or 0.

Mod(x) is always positive. Taking the positive root gives 2. Taking the negative root (regardless of what value x takes) the answer is 0.

The answer is only 2 2 .

By definition, x 2 = x \sqrt { { x }^{ 2 } } =\left| x \right| where x x is a real number.

x 2 = x = x \sqrt { { x }^{ 2 } } =\left| x \right| =x , if x 0 x\ge 0 .

x 2 = x = x \sqrt { { x }^{ 2 } } =\left| x \right| =-x , if x < 0 x<0 .

Kenneth Choo - 4 years, 11 months ago

The standard root notation means a positive square root. Answer will be 0 and 2 if the question mentions that the square root is both positive and negative root functions.

Shaumik Khanna - 3 years, 9 months ago

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The square root cannot be both positive and negative root functions together. Then, it fails to meet the criteria to be a function - the vertical line test.

Krish Shah - 1 year, 1 month ago

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Yeah, Sure a multifunction then.

Shaumik Khanna - 8 months, 2 weeks ago

I agree with this comment. The fact that some are disagreeing shows that the "convention" is not standard.

Motty Stone - 3 years, 1 month ago

Did you read the question? It says x is any non-zero real number

Rizza Mallari - 2 years, 9 months ago

absolute (X), read the question carefully

Alviando Hendriawan - 6 years ago

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the modulus (x) is the same thing as absolute (x)

Jaxon Moran - 5 years, 12 months ago
John Aries Sarza
Sep 1, 2014

The first term is just equal to 1, thus 1 + 1 = 2 1+1=2

Can't the first term also equal -1?

Srikar Bhimmanapalli - 6 years, 9 months ago

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While it is true that x 2 = ( x ) 2 x^2=(-x)^2 , x \sqrt{x} is an operator that always gives the positive root, unless it is otherwise for specific reasons (e.g. finding roots of quadratics, other algebra, etc. )

Nicolas Bryenton - 6 years, 9 months ago

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Only for functions. There is nothing in the question that states this is a function. So it is reasonable to take the negative square root.

Stevaan Hall - 6 years, 9 months ago

x \sqrt{x} never returns the negative root of a real number. This is precisely why we often write ± x \pm\sqrt{x} when we mean to refer to both roots (e.g. when finding all solutions to quadratic equations). The square root function only refers to the positive root; thus, we always must include ± \pm in order to refer to both possible real roots of a positive real number.

If x x is a real number, it is always the case that x 2 = x \sqrt{x^2} = |x| , by the standard definition of the square root function. If you ever take it to mean anything else (the negative real root of x 2 x^2 , say), then you are no longer using the standard definition of the square root function.

Andrew Droll - 4 years, 4 months ago

where did u learn that man???? that the root operator always returns the positive root lol!!!!

Somesh Singh - 6 years, 9 months ago

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@Somesh Singh It's a function that is accepted to mean the positive square root. It's just a technical thing to make our lives easier, just like how 1 isn't prime.

Nicolas Bryenton - 6 years, 9 months ago

@Somesh Singh havn't u seen the graph of square root function....its always positive...dumb

vivek kushal - 6 years, 9 months ago

\sqrt{x^2} = |x|

Ankush Chauhan - 6 years, 9 months ago

you are correct...the first term definitely can be -1...its because the mod operator always gives the positive value of every number either '+'ve or '-'ve!!! therefore ans can be 0 or 2

Somesh Singh - 6 years, 9 months ago

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The square root function is defined to always be equal to the positive root. It is true that x^2 = y has two distinct real solutions for any positive real number y, but sqrt(y) only has a single value - the positive root of y - by definition.

Andrew Droll - 5 years, 11 months ago

Dumb...read the response of Nicolas Bryenton

vivek kushal - 6 years, 9 months ago

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@Vivek Kushal watch what u say dude...i dont need lessons on basic math from anybody....mr.bryenton is saying that the root operator always gives the positive root....i have never read such a pointless rule....all i know is that the root operator returns the value as it is...for eg: root of (-9)^2 is -9 not 9...

Somesh Singh - 6 years, 9 months ago

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@Somesh Singh See my comment above. And calm down...

Nicolas Bryenton - 6 years, 9 months ago

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@Nicolas Bryenton great response brother...but i believe thats an old technique..that whenever you haven't got legitimate grounds of explanation for sumthin' you can simply end up moaning about the same old-"made to make our lives easier" assumption ;) ;) ;)

Somesh Singh - 6 years, 9 months ago

@Somesh Singh According to your reasoning, 81 \sqrt{81} , let's say, would not be well-defined. Indeed (using your reasoning), we'd have

81 = 9 2 = 9 \sqrt{81} = \sqrt{9^2} = 9

and simultaneously

81 = ( 9 ) 2 = 9 \sqrt{81} = \sqrt{(-9)^2} = -9

This means that the square root operator would not define a function. Functions always return values which are uniquely defined by their arguments, by definition. In order to make the square root operator well-defined, it is standard that x \sqrt{x} refers to the positive root of x x (when x x is a positive real number), as Nicolas indicated. This is precisely why we write ± x \pm\sqrt{x} when we mean to refer to both roots - the square root operator only returns the positive value, and so we must write ± \pm explicitly in order to refer to both roots.

Andrew Droll - 4 years, 4 months ago

@Somesh Singh what u know can not be always right....change your attitude towards maths...if u have never read it that doesn't mean it is not correct...the root operator always gives positive value

vivek kushal - 6 years, 9 months ago

no....because square root of x^2 is always +ve

vivek kushal - 6 years, 9 months ago

root of x^2 can be either x or -x, if this is the case then the ans can be 2 or 0.... correct me if am wrong...

Amrutha Purushothaman - 6 years, 8 months ago

square root of a number will always be greater or equal to zero. Then, sqrt(x²) is identical to abs(x), so the fraction is equal to 1.

So, you got, for all x, 1 + 1 = 2.

Jean-Philippe Provost - 6 years, 9 months ago

Any value you put for x after removing the radical and square will just be that number which would cancel and make it one, from there its just 1+1 any x value works. You can't possibly go wrong in this problem.

Abid Khan - 6 years, 9 months ago

x^2^(1/2)=+or-x if x^2^(1/2)=-x then IxI=-x. so first term is 1, if x^2^(1/2)=x then IxI=x so first term is 1 too. so answer is 2

Sreerag Moorkkannoor - 6 years, 9 months ago

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|x| by definition is 'positive value'. So |x|=-x makes no sense.

Stevaan Hall - 6 years, 9 months ago

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On the contrary, x = x |x| = -x certainly makes sense. It's an equation with infinitely many solutions - those solutions being the set of all real numbers x x satisfying x 0 x \leq 0 (that is, the non-positive real numbers).

Andrew Droll - 4 years, 4 months ago

actually, the square root of x^2 can yield a negative value as well... so the answers are 2 and 0...

Ashvini Shah
Oct 19, 2014

2 and 0 both are correct.

Raj K Ra
Sep 29, 2014

I think, |x| means just the magnitude of x (i.e if x is negative mod x will be positive) and thus the denominator will always be positive irrespective of numerator. Sqrt(x^2) = +x or -x => Sqrt(x^2)/|x| = +1 or -1, so this can have two solutions either 0 or 2.

Aditya Chary
Sep 4, 2014

|x|=x if x> or equal to 0 |x|= -x if x is less than 0 so if we take x as positive number then its root of its square will be positive as well as its mod will be positive and if we take x as negative number then root of its square is negative as well its mod negative so in both cases the answer will be 2

Root over of X^2 = |x| so 1/1+1=2..

Dharmendra Kumar - 6 years, 9 months ago
Mohammad Khaza
Jul 7, 2017

√(x^2) =x

so, x/x =1

and ,1+1 =2

Usama Ejaz
Oct 4, 2015

the square root of x square is absolute x. absolute x over absolute x is 1 (both cut each other) 1 + 1 = 2

Ayush Sharma
Sep 22, 2015

I don't understand

Arjang Fahim
Jan 1, 2015

Two is not the only answer. Zero is also another possible answer. But when I entered 0 it didn't take it as correct answer!

Yes, I agree with you. (x)²= x² and (-x)²= x², implying that √x²= x or -x. |x| is always positive x. Therefore, the two possibilities are (-x/x)+1= 0 and (x/x)+1= 2. I'm surprised that 0 isn't accepted as a possible answer!

Aran Pasupathy - 6 years, 4 months ago

The answer is only 2 2 .

By definition, x 2 = x \sqrt { { x }^{ 2 } } =\left| x \right| where x x is a real number.

x 2 = x = x \sqrt { { x }^{ 2 } } =\left| x \right| =x , if x 0 x\ge 0 .

x 2 = x = x \sqrt { { x }^{ 2 } } =\left| x \right| =-x , if x < 0 x<0 .

Kenneth Choo - 4 years, 11 months ago
Huxley Smith
Nov 4, 2014

doesnt actually work root of something can be either negative or positive you get either 2 or 0

Teja Allani
Sep 11, 2014

sqrt(x^2)=|x| => |x|/|x|=1=> |x|/|x|+1=1+1=2

Jao Garcia
Sep 9, 2014

LOL WHY DO YOU GUYS DO HAVE SOLUTIONS FOR THIS? x is just any number. Plug in any number lol to x, and you will always get "2"

"Plug in any number lol to x, and you will always get "2""

How do you know? This is what solution is for...

Micah Wood - 6 years, 9 months ago
Jord W
Sep 9, 2014

i think it should make it clear that x is positive, otherwise it could also be 0

Dladla Arthur
Sep 4, 2014

The first term x/x or -x/-x which is just 1.

therefore:

1+1 = 2

first term is either x/x=1 or -x/x=-1 so its 0 or 2

Priyadarshan KV - 6 years, 8 months ago
Aditi Korgaonkar
Sep 4, 2014

as x is a non zero real no.the value of 1st term will be x/x=1 and thus 1+1=2

i agree... (Y)

Cyndmark Penaso - 6 years, 7 months ago
Tamoghna Purkait
Sep 4, 2014

Root over of X^2 = |x|

Bostang Palaguna
Sep 21, 2020

by definition: x 2 = x \sqrt{x^2} = |x| . Thus, the following question will be 1 + 1 = 2

Oon Han
Jul 10, 2019

Remember that x 2 = x \sqrt{x^2} = |x| . x 2 x + 1 = x x + 1 = 1 + 1 = 2 \begin{aligned} \frac{\sqrt{x^2}}{|x|} + 1 &= \frac{|x|}{|x|} + 1 \\ &= 1 + 1 \\ &= \boxed{2} \end{aligned}

Therefore, the answer is 2 .

Andrew Droll
Jan 14, 2017

For any real number x x not equal to 0 0 , there are two distinct complex numbers whose squares are equal to x x .

However, this does not mean that x \sqrt{x} has two values. By convention, the square root function is defined such that x \sqrt{x} is equal to the unique positive real number whose square is x x , whenever x x is a positive real number. Also, 0 = 0 \sqrt{0} = 0 . The value of x \sqrt{x} is not defined when x < 0 x < 0 (the domain of the function is the nonnegative real numbers).

In fact, this definition is precisely why the solution to x 2 = y x^2 = y , say, is x = ± y x = \pm \sqrt{y} (when y y is a positive real number). Here, y \sqrt{y} is defined to be the unique positive root of y y . Thus, to list all solutions to the equation, we actually have two possibilities: x = y x = \sqrt{y} and x = y x = -\sqrt{y} . We write x = ± y x = \pm\sqrt{y} as shorthand for these two possibilities. This notation does not indicate that y \sqrt{y} has two values (the opposite, actually).

In this question, x 2 x^2 is guaranteed to be a positive real number, because x x is a non-zero real number. x 2 \sqrt{x^2} is the unique positive number which squares to x 2 x^2 - in other words, x 2 \sqrt{x^2} is equal to x |x| (uniquely).

So the expression should be simplified to

x 2 x + 1 = x x + 1 = 1 + 1 = 2 \frac{\sqrt{x^2}}{|x|} + 1 = \frac{|x|}{|x|} + 1 = 1 + 1 = 2

2 2 is the unique answer to this problem.

N.B. It is only true that x 2 = x \sqrt{x^2} = x when x 0 x\geq 0 . In general, x 2 = x \sqrt{x^2} = |x| for real x x , by definition. This definition is taken as a matter of convention in order to allow the definition of a square root function from R + R \mathbb{R}^+ \rightarrow \mathbb{R} at all (the value of a function must always be uniquely defined by its arguments).

Ayako Cleavin
Jul 21, 2016

X is not zero .then let x is 1 . Let I square + 1 = 1+1= 2. Therefore answer is 2.

Gwen Julius
Jul 10, 2016

What about imaginary number? Where i can be a negative number. So √i can be -1. Any advise? I was taught this way. Now I'm confused.

Kayla Medeiros
Dec 8, 2015

The square root of a number squared is just that number so √x^2 is just x. it must be positive because for example -2^2=4 then square that is just 2. In this equation x=1 so √1^1+1 is simply 1+1=2

Shree Tej
Dec 1, 2015

but what if x = 0 ????/

x square root is the same thing as x. So if you take x as 10 so 10/10 gives you one so you will add another 1 to it and get the answer 10

If x=10 then 10/10+1 =1+1 =2 (the answer)

Arvind Patel
Nov 19, 2015

Agree, it has to be 0 or 2. Both are possible solutions.

Seán Vaeth
Oct 16, 2015

I feel that this neglects the possible solution i + 1 and should say that x is any positive number

Sina Nakhkoob
Oct 11, 2015

Since the square route of x^2 = |x|, then the square root of x^2/ |x| + 1 = 1 + 1=> 2

Jt Perry
Oct 9, 2015

± x \pm\sqrt{x} is the notation used when we want both the positive and negative root of a number.

x \sqrt{x} is the notation referring to the positive root.

ergo the answer is 2.

Silvia Woods
Sep 30, 2015

Why can't it be zero? if the number is negative it can be....

Avinash Kumar
Sep 16, 2015

Case-I.

If x<0, then (x)^2= x^2.

So , √(x^2) = - x , as x< 0.

And | x| = - x ; as x<0.

Then 【 √(x^2) ÷ |x| 】+1 = (-x/-x) + 1 =1+1= 2

Case-II

If x>0 , then √[ x^2] = x, as x>0.

And |x| = x, as x>0.

Then 【 √(x^2) ÷ |x| 】+ 1 = (x/x) +1 = 1+1 = 2

Hence, in both the cases ; the answer is 2.

Usama Kaim Khani
Sep 9, 2015

put the value x=1 and (1)/1+1=2 It is ao easy.....

Remus Lupin
Aug 26, 2015

Sqrt(x^2) = x. x/x = 1. 1 + 1 = 2 . It's as simple as that

Dileep kumar .S
Aug 25, 2015

I think the Only Answer is 2.....; even If x is -ve, x^2 is +ve. and then comes square root. so it is always 1+1 = 2

Leo Arifsandi
Aug 24, 2015

√x²=x .. x/x = 1 .. 1+1 = 2

Ryan Hong
Aug 23, 2015

Treat x as 1. The square root of 1 squared is 1. The absolute value of 1 is 1. 1/1 is 1. 1+1 = 2

Faysal Mahedi
Aug 20, 2015

Its positive when square root are given and so all the real numbers can set here and it will be positive

cancel square root and square it becomes (x/x) + 1 then ; let x = 1 ; and it becomes like this (1/1) + 1 = 1+1 = 2 that's it!

Sanga Crush
Aug 17, 2015

√x²÷x+1== x÷x + 1 ==→ 1+1==→2

(x^2)^1/2=+x or -x.

If it is +x then x>0, |x|=x.

If it is -x, then -x<0, |x|=-x.

Hence in both cases the answer is 2.

P.S.- we know that |x|= -x, for x<0 and +x for x>0.

Caiden Cleveland
Aug 5, 2015

I'll try to make this as simple as possible since some don't know how. Ok first the square root of x^2 is just x and anything divided by itself is 1, add 1 more and you get 2 very simple.

Vasudha Pandey
Aug 5, 2015

SInce it is given that X can not be zero I.e.x is a non zero.when X is cumng out of sqr root then negative value of X is rejected therefore we are now left with only positive value of X. \sqrt{X} divided by X gives us 1.so 1+1 = 2

Hafiz Ahmed
Aug 1, 2015

suppose X=1

Chelsea Long
Jul 31, 2015

Even if x is negative, the answer would be 2.

If x is negative, the square would be positive. Then the square root would also be positive.

The square root of x^2 would be the equivalent of the absolute value of x, so dividing them would equal 1.

1+1=2.

Bhavna Joshi
Jul 28, 2015

My sir says that it's a misconception that √x^2 = +/- x. √x^2=+x and -√x^2 = -x.

Daniel Aniel
Jul 27, 2015

I solved it like a normal fractional expression; set the denominator of +1 to 1, and solve from there. Keep in mind that the absolute value of x = the root of the square of x = x. you should eventually end up with something like 2x/x. Cross-out the x's and voila, you have 2 (sorry for the verbal description. I don't really know how to use LaTex)

Robert Medrick
Jul 27, 2015

I got the right answer of 2, but I don't understand the comma and no equals sign, what does that mean?

Meghna Shukla
Jul 27, 2015

root x square /x+1 root and square will cancel and we will get x/x+1 , when we take LCM we get , x+x/x which gives 2x/x x and x gets cancelled and we get 2 so answer is 2

Adarsh Mahor
Jul 17, 2015

√x^2=x &lxl=(+x)or(-x) So-x/lxl+1=1+1=2 Or,x/lxl+1=(-1)+1=0 But 0is not in option so answer is 2

Eshan Kapoor
Jul 16, 2015

Say, a^2 = x Then: a=+Sqrt(x), - Sqrt(x)

Square Root sign, called radical, means principal/positive square root. E.g., 5 and -5 are two square roots of 25, but if we write 25 inside radical, it means 5 and not - 5. Use Plus Minus sign for all possible solutions.

Therefore, the answer is 2.

Alex Neiman
Jul 9, 2015

I just substituted 1 in for x because the square root of 1 is 1 and the absolute value of 1 is also 1 Then I simplified.

Syed Baqir
Jul 5, 2015

\sqrt{x^2}=\:x\:why\:\left|x\right|

The answer is 2, read the question, where X is a non zero real number :D

Moatasim Hisham
Jun 18, 2015

The solution can be either 0 or 2 as it depends on the value of x being non-zero. If x is negative then the solution is zero -1+1=0 and if it is positive then the solution will be that positive x and positive x will cancel each other out giving positive 1, hence 1+1=2

since sqrt(x) = mod(x)

Shubham Gaikwad
May 29, 2015

Root Of x square is x , and absolute x is also x , therefore x/x is 1 ,and 1=1 is 2 . division of both number will always be 1 thas y the answer is 2

Joseph P
May 16, 2015

I'm really 16 and I guessed the answer 2

Quintessence Anx
May 3, 2015

The crux of this problem is x 2 x \frac{\sqrt{x^2}}{ \left|x\right|}

One piece at a time, simple first: x = x \left|x\right| = x

Just to be clear: this is always positive because it is an absolute value. This is never -x.

Second piece: x 2 = x \sqrt{x^2} = x

This is also always positive because you are taking the sqrt of x^2 and x^2 is always positive. Since only positive x is used, then the only solution is 2 .

Note that if the equation used sqrt(x), then you would need to account for both the negative and positive solutions (i.e. -sqrt(x), sqrt(x)).

Answer is non zero

Sam Wilson - 5 years, 7 months ago

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Not sure what you were looking to add with that?

Quintessence Anx - 5 years, 7 months ago

This is a good attempt, but unfortunately almost none of your answer is correct. There are some subtle problems:

First, it is not always true that x = x |x| = x . In fact, if x < 0 x < 0 (and also if x = 0 x = 0 ), we have x = x |x| = -x . This is relevant for this problem, because the problem only specifies that x x is non-zero ( x x may be negative). For example, if x = 1 x = -1 , we see that

x = 1 = 1 = ( 1 ) = x |x| = |-1| = 1 = -(-1) = -x .

It is also not always true that x 2 = x \sqrt{x^2} = x . Exactly as above, if x < 0 x < 0 (and also if x = 0 x = 0 ), then x 2 = x \sqrt{x^2} = -x . And again, for example, if x = 1 x = -1 :

x 2 = ( 1 ) 2 = 1 = 1 = ( 1 ) = x \sqrt{x^2} = \sqrt{(-1)^2} = \sqrt{1} = 1 = -(-1) = -x

In fact, what is always true is that x 2 = x \sqrt{x^2} = |x| . Your answer ( 2 2 ) is correct, but the subtle errors in reasoning here are important (and seem to be common among solutions to this problem stated here).

N.B. The square root function is defined always to return the positive root of any positive number x x . This is why we write ± x \pm\sqrt{x} explicitly when we mean to refer to both the positive and negative roots of x x .

Andrew Droll - 4 years, 4 months ago

since x is a non real number i.e is x>0 hence answer is 2

Peter Casturao
Jan 31, 2015

Write a solution. "The square root of any number squared is that number itself. That number represented by X is then divided by absolute value of itself, which is1. THEREFORE 1+1=2.

Ni'Casey Mahone
Jan 6, 2015

Rather than complicating things, or even over-thinking the problem, I took to sheer basics. The stipulations for "x" were a non zero real number. Subsequently speaking the next real number following 0 is 1. By substituting 1 for "x," our finish product is in fact 2.

Proof: Numerator: The square root of 1 is 1. 1 squared is still 1. Denominator: The absolute value of any number is the positive number itself; |1| = 1. So we have 1/1. The result of dividing 1 by 1 is still 1. Finally we arrive to a simple equation, 1+1 and as we all know the result is 2.

Nice and simply, just substitute 1 for "x. "

Jane Daphni
Dec 24, 2014

(x^2)^1/2=mod x

akar x kuadrat=x x:x =1 1+1=2

Carl Beaupre
Dec 19, 2014

square root of x squared is x. x divided by x is 1. 1 plus 1 is 2.

John Church
Dec 15, 2014

Karthik is correct !

Kelly Ogilvie
Dec 14, 2014

The square root of x squared is just x, so you can reduce this equation to x x + 1 \frac{x}{x} +1 , which becomes 1 + 1, or 2.

Since absolute value is imposed for the denominator, the value of x, whether negative or positive, will end up positive. The numerator has been squared, so whether it's negative or positive, it will end up positive. The square root of a positive number has two solutions, a positive one and a negative one, so the final answer can either be 2 or zero. However, the equation does not require both roots (usually indicated by a +- in front of the equation, like in the quadratic formula), meaning we are to use the PRINCIPAL root, which is the positive number, so the answer is 2.

Hannah-Beth Hall
Dec 12, 2014

|x| has to be bigger than 0. anything sqrooted also has to be bigger than 0. therefore it its just x^2 which is sqrooted to x, then devide this by x, therefore 1 + 1 = 2

{(x^2)^0.5}/x + 1 = 2

Abhay Minachi
Dec 8, 2014

Since Mod of X is always +ve quantity...Answer is 2

Ashraf Ahmed
Dec 8, 2014

i'll write solution by ِِArabic: الجذر التربيعي لاكس أس 2 يساوي اكس اكس علي اكس يساوي واحد واحد+واحد يساوي 2

Chandan Kumar
Dec 7, 2014

x/x+1=2x/x=2

Babu Siluveru
Dec 7, 2014

Root of one number has always has two solutions i.e -ve and +ve. so even if x*x results in positive and after that root of that number results in two intezers i.e +ve and -ve and so it results in two answers one is 2 and the other is 0.

Rohit Sharma
Dec 6, 2014

square and square root gets cancelled and denominator becomes "x" . therefore x/x=1 and 1 +1 = 2

Leme Asyu
Dec 5, 2014

sqrt of x^2 = x , so x/x +1 =2

Shuaib Muhammad
Dec 4, 2014

x /x + 1 = 1 +1 = 2

Mohit Garg
Dec 2, 2014

Either you choose positive no. or negative no. , the first term in the expression becomes 1 , so answer is 1+1=2

Kunal Mandal
Nov 29, 2014

Given ans. is 2. But considering +/- values of sq. root of x*x, the other ans. can be 0

Mitesh Shah
Nov 26, 2014

1+1=2 The square root and squared functions basically cancel out, and since the denominator x is already positive, the absolute value doesn't matter

Jack Saraceno
Nov 24, 2014

(sqrt(x))^2 = |x|. |x|/|x| = 1. 1+1 = 2

x^(1/2)=X x/x=1 1+1=2

Square the entire thing. √x2 becomes x2. |x| becomes x2. Squaring 1 yields 1. x2/x2 = 1 + 1 = 2 ans.

Elias Green
Nov 19, 2014

When the question says, "x is any real number," this usually implies that if you insert any number into the equation, then it will give you the answer. Just in case though, you should try inserting multiple different values for x. For example in this problem, if x equals 1 then the answer is 2, and if you say x equals 2 the answer is still 2.

Saanika Gupta
Nov 18, 2014

IT MEANS (x/x)+1=1+1=2

Dipen Katekhaye
Nov 17, 2014

i was first confused that if could be 0 too, but 2 is for sure. because, it's modulus of value.

Aaron S
Nov 16, 2014

The radical symbol by convention is set to equal the positive root, so the square root of x squared is always positive for any non-zero real number. Therefore absolute value of x and square root of x squared are always the same value and when divided equal one. Add one to get two, the final answer.

Shanthan Palle
Nov 16, 2014

In mathematics |x| of real number of x is non-native value so √x^2 = x and |x| = x

so x/x+1 = 2

Christina Johnson
Nov 16, 2014

(X^1/2)(X^2) = x , X/x=1, 1+1=2

Md Moniruzzaman
Nov 16, 2014

√X/│X│+1. Where x=1 →√1/│1│+1=2.

Ikramul Hoque
Nov 13, 2014

x^2 is always +ve . so square root of x^2 is +ve. Hence x/x+1=1+1=2. only ans is 2.

Fathy Ali
Nov 13, 2014

The correct answer is not just 2, it may be 2 or 0 as the sqrt of any number has two solutions +x and -x. the solution would be 2 only if we are dividing by x not |x|

Amit Kumar
Nov 11, 2014

if X is a non zero real number (X^2)^1/2=IxI, thus, the above equation will always be number 1+1=2

Sohail Hameed
Nov 11, 2014

This has two solutions. 0 and 2. No argument.

Rajendran Balaji
Nov 7, 2014

always root of x square will be x. so the root and square get cancelled . Now the sum is x divided by x +1. so the x and x get cancelled and it becomes 1 and 1+1=2 so the answer is 2

(sqr root of x^{2}) =IxI
IxI/IxI=1
hence, the ans is 1+1=2

Kai Millner
Nov 3, 2014

Because the "x" in the square root is being squared, it has to be positive. Same thing with the absolute value.

Isabella Tirado
Nov 3, 2014

The square root and squared functions basically cancel out, and since the denominator x is already positive, the absolute value doesn't matter. These are just making everything more complicating. So now you have x/x, and any number divided by itself is one, so now you have 1+1, which is obviously 2.

Mikayla Elverson
Nov 3, 2014

I used the number one, because it is a non zero real number. Of course, it is a relatively easy number to use, that is why I chose it for explaining.

So, first I plugged in x as 1, and got the square root of one squared is 1, over the absolute value of 1+1.

That would equal 1/1+1, which is 1+1. 1+1=2, and two is a correct solution, as I have been told by the guide.

Andy Smith
Oct 29, 2014

The square root notation (without sign) represents the POSITIVE square root. It follows that;

x = x 2 \boxed{|x| = \sqrt{x^2}}

which is sometimes used as a definition of absolute value.

Therefore;

x 2 x = x 2 x 2 = x x = 1 \frac{\sqrt{x^2}}{|x|}=\frac{\sqrt{x^2}}{\sqrt{x^2}}=\frac{|x|}{|x|}=1

and the equation simply becomes;

1 + 1 = 2. 1+1=2.

Avik B
Oct 28, 2014

The answer should be 2 or 0 as square root of X will have both +X and -X as solution. Mod X will always be positive. So for +X in numerator answer is 2 and for -X its 0

Square always shows that a number is positive . x may be +ve or -ve For example:Let x = -5 or 5 The square of -5 and 5 both equals to 25 and square root of 25 = 5 and also |5| = |-5| = 5 => 5/5 +1 = 1+1 = 2 Answer

Priyadarshan Kv
Oct 12, 2014

it can b either 2 or 0

Sagar Agrawal
Oct 10, 2014

It's Just simple , if u take x=2 than ^x wil be 4 and x = 2 , apply L.c.m = 2+2/2 Ans ! = 2

Evan Sokol
Oct 6, 2014

Another answer would be zero unless it's specified that we are taking the principal or positive square root. If we had (sqrt(x^2))^2 + 1 then our only answer would be two as it no longer matters if the square root is positive or negative in that case.

Purrab 1109
Oct 4, 2014

Because mod(X) is always a positive value there the first fraction is equal to 1 therefore the answer is 1+1=2

Satya Kanna
Oct 1, 2014

in this problem they ask non zero real numder so x=2.then root and power 2 chancl we get 2/2=1 now 1+1 =2 now ans is 2

Huzaifa Khan
Sep 26, 2014

Given: x is a non zero real number

Step 1: consider x as a least non zero real number. let say x= 1 Step 2: substitute x in the given equation. Step 3: solving it we get 1+1=2

Note: This result is true for all non zero real numbers.

Arvin Gonzales
Sep 24, 2014

the root of x squared is1 , the value of x is 1 so that 1+1=2

Rais Ahmad
Sep 19, 2014

square root of every non zero number is always positive (Even the value of X is -ve). So its comes 2, every value of X

Sankalp Yadav
Sep 15, 2014

same as kartik solution . u should refer to graph plotiing of root x^2

Keyur Rangani
Sep 15, 2014

As x is a real no. x1/2=|x|

And thus 1+1=2

Tyler Schommer
Sep 14, 2014

When a variable such as x is squared, the value of x as a whole is squared, meaning x^2 will always be a positive number. The square root reduces result of x^2 to just x, while the bottom will always be positive x. Any value divided by itself will always be 1, so x/x = 1. And, as always, 1 + 1 = 2

Ken Raquepo
Sep 13, 2014

square root and exponent can be cancelled and when you divide the number by itself, the answer is one, so then you'll end up with 1+1=2 :)

Romeo, Jr Madrona
Sep 13, 2014

2 or 0.

If x>o, the ans is 2. If x<0, the ans is 0.

Siddharth Mishra
Sep 11, 2014

frnds mod of |x| or any number gives always +ve value and root of x^2 is x and it's also a +ve so on solving it gives answer 2..

Square and root which after a simple simplification gives us +ve "X" and modules of x is "X" . So its gives us 1 and 1+1=2

Lavaney Thakral
Sep 10, 2014

(x)^2=(-x)^2
But Root of (x)^2 = x
While Root of (-x)^2 = -x
Hence Here, Root of (x)^2 = x
|x| = x
Hence, 1+1=2




Allen Peterson
Sep 4, 2014

Square root of x^2=x then, |x|=+-x but x is a non zero real number. Because, |x|=x then, x/x=1 1+1=2.

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