Evaluate
∣ x ∣ x 2 + 1 ,
where x is a non-zero real number.
This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
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.
Log in to reply
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,
Log in to reply
why is tht?
square root of any number can be both positive and negative. sqrt(3^2) =sqrt(9)=+3,-3
But a square root is always a positive and negative solution
Log in to reply
@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.
@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.
if a^2=x^2 then a=+x or -x but Sqrt(x^2)=|x| always
By convention the radical symbol returns the positive root.
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
Log in to reply
Actually it should be stated in the problem clearly...
Log in to reply
@Gaurav Yadav – It already is. Who uses the symbol to mean both roots?
x is only the inverse of x 2 on the interval [ 0 , ∞ ) .
"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.
(2,0) i think correct answer if i am wrong plz tell correct answer
Log in to reply
square root of x^2 is x/x=1+1=2
I think u are right
The answer is only 2 .
By definition, x 2 = ∣ x ∣ where x is a real number.
x 2 = ∣ x ∣ = x , if x ≥ 0 .
x 2 = ∣ x ∣ = − x , if x < 0 .
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
Log in to reply
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
Log in to reply
@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.
Log in to reply
@Christopher Audino – tell me man where it is mentioned "square root" is the "positive square root" .
Log in to reply
@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.
@Rachit Sharma – "where x is a non zero real number." --> non-zero real number means start from +1.
Log in to reply
@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.
Log in to reply
@Karan Babar – Actually, since the term evaluates to some form of 0/0, that is not infinity, but is truly undefined.
@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.
Log in to reply
@John Armstrong – True story bro.
@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
@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"
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.
why is that only?
Log in to reply
Because, always, both, root of x and mod x are positive.
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.
Log in to reply
correct! That |x|=3 step is what most people never come to know in school :)
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
The square root function always returns positive values .
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.
For any real number x not equal to 0 , there are two distinct complex numbers whose squares are equal to x .
However, this does not mean that x has two values. By convention, the square root function is defined such that x is equal to the unique positive real number whose square is x , whenever x is a positive real number. Also, 0 = 0 . The value of x is not defined when 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 , say, are denoted x = ± y (when y is a positive real number). Here, y is defined to be the unique positive root of y . Thus, to list all solutions to the equation, we actually have two possibilities: x = y and x = − y . We write x = ± y as shorthand for these two possibilities. This notation does not indicate that y has two values (the opposite, actually).
In this question, x 2 is guaranteed to be a positive real number, because x is a non-zero real number. x 2 is the unique positive number which squares to x 2 - in other words, x 2 is equal to ∣ x ∣ (uniquely).
So the expression should be simplified to
∣ x ∣ x 2 + 1 = ∣ x ∣ ∣ x ∣ + 1 = 1 + 1 = 2
2 is the unique answer to this problem.
N.B. It is only true that x 2 = x when x ≥ 0 . In general, x 2 = ∣ x ∣ for real 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 at all (the value of a function must always be uniquely defined by its arguments).
N.B. #2 If x is a real number, it is always the case that 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 , say), then you are no longer using the standard definition of the square root function.
Log in to reply
Your answer dispels all my doubts. Very well written!
the answer is 2!! hehehe :p i got it so easily. did anyone else?
any +ve number
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.
Log in to reply
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.
Fudge the formatting guide, x^2 * x^0.5 = x^1
Log in to reply
Wrong. x^2 * x^0.5 = x^2.5, because you're supposed to ADD the exponents.
x/ |x| =n^. so, n^+1 = 2...
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)
Log in to reply
if x equals, let us say 2 i , then:
x 2 = ( 2 i ) 2 = 2 2 × i 2 = 4 × i 2 = 2 i
Also, ∣ 2 i ∣ = ∣ 2 ∣ i = 2 i
So, x 2 / ∣ x ∣ + 1 = 2 i / 2 i + 1 = 2
Even if x is a negative imaginary, like if x = − 3 i , then:
x 2 = − 3 i 2 = − 3 2 × i 2 = 9 × i 2 = 3 i
And ∣ − 3 i ∣ = ∣ − 3 ∣ i = 3 i
So, x 2 / ∣ x ∣ + 1 = 3 i / 3 i + 1 = 2
The answer is only 2 in every case, not 0.
Log in to reply
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 only when either/both of a and b ≥ 0 .
It is stated in the problem that x is a non-zero real number.
If x is in the form b i where b is a non-zero real number and i 2 = − 1 , then ( b i ) 2 = ∣ b ∣ i .
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?????????????
Log in to reply
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.
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
Log in to reply
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.
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.....
Log in to reply
And divide by zero my phone will blow up if I typed in 0
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
Log in to reply
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.
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
2... since its a non zero real number
so do i ch ali.
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 .
I disagree with u.What we are doing here is also equation solving. This problem has 2 solutions: 0 or 2.
Log in to reply
This is not an equation. It's an expression.
By definition, x 2 = ∣ x ∣ where x is a real number.
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.
Log in to reply
By definition, x 2 = ∣ x ∣ where x is a real number.
It is false because root of a number can be positive or negative
Log in to reply
square root of a number is always non-negative; it is the roots of a quadratic polynomial that can be both positive and negative.
No square root always returns positive values .
x 2 = ∣ x ∣
Log in to reply
You mean nonnegative values. Zero is the sqrt of zero.
Log in to reply
@Whitney Clark – Yeah . Thanks for the correction. :)
If there is an x, there is an equation
This is wrong. It's 0 and 2
Log in to reply
No it isn't. The sqrt symbol refers to the principal root ONLY.
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!
Log in to reply
It is defined that x 2 = ∣ x ∣ , where 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
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!
But how are you supposed to refer to them individually?
the key is x is a non zero real number, so it can not be 0..
√x2/|x|+1=+1+1=2:-1+1=0
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 .....!!
Log in to reply
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.. :-)
Log in to reply
But it wouldn't accept two values i.e 2 & 0. :(
Log in to reply
@Keshav Gaur – yeah it wont accept...but its the publisher's fault isn't it...
Log in to reply
Log in to reply
@Vicky Andrew – Example 2 is incorrect, lets rewrite that as ((-4)^2)^(1/2)=(-4)^(2/2)=(-4)^1= -4
@Vicky Andrew – Disagree with example 2. The square root can take a positive or negative value.
@Vicky Andrew – thnx sir!!!
@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.
@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 ∣ x 2 = 4 4 2 = 4 1 6 = 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
Log in to reply
@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. :)
Log in to reply
@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.
@Alex Carter – Because you wnat it!!!Common sense in this case exponencial before square root...
Log in to reply
@Márcio Nascimento – The square root is an exponent too, it is just to the 1/2 power.
@Alex Carter – It is written "where x is a non zero real number" so we know that the root should be positive, not negative.
Log in to reply
@Garvin Goei – I'm afraid that there are 2 things wrong with that statement:
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.
Real numbers can be +ve or -ve. This only rules out the inclusion of imaginary numbers, i.e. x^2 cannot be -ve.
@Somesh Singh – no its your fault
@Keshav Gaur – Who said it cannot hv two values. Its an equation, can have any number of values!
square root of x^2 is not 'x' it is mod(x) hence the ans is 2 only not 0
Log in to reply
@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 :) :) :)
Log in to reply
@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
correct but root of (-4)^2 is also 4
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.
the answer is 0,2 because the square root has -,+ answers if its even.
But |x| also equals to x and -x.
Log in to reply
For all real numbers x ,
x 2 = ∣ x ∣ = x , if x ≥ 0 ,
x 2 = ∣ x ∣ = − x , if x < 0 .
Not at all confusing or hard >>>
root x^2 = x / |x| + 1
x/x+1
1+1
2 ........ really simple question ... :)
Log in to reply
It's not that simple. there will be 2 answers if qn was x/|x| where x is non zero real no....
Log in to reply
It's that simple.
By definition, x 2 = ∣ x ∣ where x is a real number.
But that was not the question Jino. Aasif Khan is correct
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 .
By definition, x 2 = ∣ x ∣ where x is a real number.
x 2 = ∣ x ∣ = x , if x ≥ 0 .
x 2 = ∣ x ∣ = − x , if x < 0 .
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.
Log in to reply
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.
I agree with this comment. The fact that some are disagreeing shows that the "convention" is not standard.
Did you read the question? It says x is any non-zero real number
absolute (X), read the question carefully
Log in to reply
the modulus (x) is the same thing as absolute (x)
The first term is just equal to 1, thus 1 + 1 = 2
Can't the first term also equal -1?
Log in to reply
While it is true that x 2 = ( − x ) 2 , 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. )
Log in to reply
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.
x never returns the negative root of a real number. This is precisely why we often write ± 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 ± in order to refer to both possible real roots of a positive real number.
If x is a real number, it is always the case that 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 , say), then you are no longer using the standard definition of the square root function.
where did u learn that man???? that the root operator always returns the positive root lol!!!!
Log in to reply
@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.
@Somesh Singh – havn't u seen the graph of square root function....its always positive...dumb
\sqrt{x^2} = |x|
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
Log in to reply
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.
Dumb...read the response of Nicolas Bryenton
Log in to reply
@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...
Log in to reply
@Somesh Singh – See my comment above. And calm down...
Log in to reply
@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 – According to your reasoning, 8 1 , let's say, would not be well-defined. Indeed (using your reasoning), we'd have
8 1 = 9 2 = 9
and simultaneously
8 1 = ( − 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 refers to the positive root of x (when x is a positive real number), as Nicolas indicated. This is precisely why we write ± x when we mean to refer to both roots - the square root operator only returns the positive value, and so we must write ± explicitly in order to refer to both roots.
@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
no....because square root of x^2 is always +ve
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...
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.
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.
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
Log in to reply
|x| by definition is 'positive value'. So |x|=-x makes no sense.
Log in to reply
On the contrary, ∣ x ∣ = − x certainly makes sense. It's an equation with infinitely many solutions - those solutions being the set of all real numbers x satisfying x ≤ 0 (that is, the non-positive real numbers).
actually, the square root of x^2 can yield a negative value as well... so the answers are 2 and 0...
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.
|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..
√(x^2) =x
so, x/x =1
and ,1+1 =2
the square root of x square is absolute x. absolute x over absolute x is 1 (both cut each other) 1 + 1 = 2
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!
The answer is only 2 .
By definition, x 2 = ∣ x ∣ where x is a real number.
x 2 = ∣ x ∣ = x , if x ≥ 0 .
x 2 = ∣ x ∣ = − x , if x < 0 .
doesnt actually work root of something can be either negative or positive you get either 2 or 0
sqrt(x^2)=|x| => |x|/|x|=1=> |x|/|x|+1=1+1=2
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...
i think it should make it clear that x is positive, otherwise it could also be 0
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
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)
by definition: x 2 = ∣ x ∣ . Thus, the following question will be 1 + 1 = 2
Remember that x 2 = ∣ x ∣ . ∣ x ∣ x 2 + 1 = ∣ x ∣ ∣ x ∣ + 1 = 1 + 1 = 2
Therefore, the answer is 2 .
For any real number x not equal to 0 , there are two distinct complex numbers whose squares are equal to x .
However, this does not mean that x has two values. By convention, the square root function is defined such that x is equal to the unique positive real number whose square is x , whenever x is a positive real number. Also, 0 = 0 . The value of x is not defined when 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 , say, is x = ± y (when y is a positive real number). Here, y is defined to be the unique positive root of y . Thus, to list all solutions to the equation, we actually have two possibilities: x = y and x = − y . We write x = ± y as shorthand for these two possibilities. This notation does not indicate that y has two values (the opposite, actually).
In this question, x 2 is guaranteed to be a positive real number, because x is a non-zero real number. x 2 is the unique positive number which squares to x 2 - in other words, x 2 is equal to ∣ x ∣ (uniquely).
So the expression should be simplified to
∣ x ∣ x 2 + 1 = ∣ x ∣ ∣ x ∣ + 1 = 1 + 1 = 2
2 is the unique answer to this problem.
N.B. It is only true that x 2 = x when x ≥ 0 . In general, x 2 = ∣ x ∣ for real 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 at all (the value of a function must always be uniquely defined by its arguments).
X is not zero .then let x is 1 . Let I square + 1 = 1+1= 2. Therefore answer is 2.
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.
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
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)
Agree, it has to be 0 or 2. Both are possible solutions.
I feel that this neglects the possible solution i + 1 and should say that x is any positive number
Since the square route of x^2 = |x|, then the square root of x^2/ |x| + 1 = 1 + 1=> 2
± x is the notation used when we want both the positive and negative root of a number.
x is the notation referring to the positive root.
ergo the answer is 2.
Why can't it be zero? if the number is negative it can be....
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.
put the value x=1 and (1)/1+1=2 It is ao easy.....
Sqrt(x^2) = x. x/x = 1. 1 + 1 = 2 . It's as simple as that
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
√x²=x .. x/x = 1 .. 1+1 = 2
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
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!
√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.
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.
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
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.
My sir says that it's a misconception that √x^2 = +/- x. √x^2=+x and -√x^2 = -x.
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)
I got the right answer of 2, but I don't understand the comma and no equals sign, what does that mean?
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
√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
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.
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.
\sqrt{x^2}=\:x\:why\:\left|x\right|
The answer is 2, read the question, where X is a non zero real number :D
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)
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
I'm really 16 and I guessed the answer 2
The crux of this problem is ∣ x ∣ x 2
One piece at a time, simple first: ∣ x ∣ = x
Just to be clear: this is always positive because it is an absolute value. This is never -x.
Second piece: 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
Log in to reply
Not sure what you were looking to add with that?
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 . In fact, if x < 0 (and also if x = 0 ), we have ∣ x ∣ = − x . This is relevant for this problem, because the problem only specifies that x is non-zero ( x may be negative). For example, if x = − 1 , we see that
∣ x ∣ = ∣ − 1 ∣ = 1 = − ( − 1 ) = − x .
It is also not always true that x 2 = x . Exactly as above, if x < 0 (and also if x = 0 ), then x 2 = − x . And again, for example, if x = − 1 :
x 2 = ( − 1 ) 2 = 1 = 1 = − ( − 1 ) = − x
In fact, what is always true is that x 2 = ∣ x ∣ . Your answer ( 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 . This is why we write ± x explicitly when we mean to refer to both the positive and negative roots of x .
since x is a non real number i.e is x>0 hence answer is 2
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.
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. "
akar x kuadrat=x x:x =1 1+1=2
square root of x squared is x. x divided by x is 1. 1 plus 1 is 2.
The square root of x squared is just x, so you can reduce this equation to 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.
|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
Since Mod of X is always +ve quantity...Answer is 2
i'll write solution by ِِArabic: الجذر التربيعي لاكس أس 2 يساوي اكس اكس علي اكس يساوي واحد واحد+واحد يساوي 2
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.
square and square root gets cancelled and denominator becomes "x" . therefore x/x=1 and 1 +1 = 2
Either you choose positive no. or negative no. , the first term in the expression becomes 1 , so answer is 1+1=2
Given ans. is 2. But considering +/- values of sq. root of x*x, the other ans. can be 0
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
(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.
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.
i was first confused that if could be 0 too, but 2 is for sure. because, it's modulus of value.
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.
In mathematics |x| of real number of x is non-native value so √x^2 = x and |x| = x
so x/x+1 = 2
(X^1/2)(X^2) = x , X/x=1, 1+1=2
√X/│X│+1. Where x=1 →√1/│1│+1=2.
x^2 is always +ve . so square root of x^2 is +ve. Hence x/x+1=1+1=2. only ans is 2.
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|
if X is a non zero real number (X^2)^1/2=IxI, thus, the above equation will always be number 1+1=2
This has two solutions. 0 and 2. No argument.
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
Because the "x" in the square root is being squared, it has to be positive. Same thing with the absolute value.
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.
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.
The square root notation (without sign) represents the POSITIVE square root. It follows that;
∣ x ∣ = x 2
which is sometimes used as a definition of absolute value.
Therefore;
∣ x ∣ x 2 = x 2 x 2 = ∣ x ∣ ∣ x ∣ = 1
and the equation simply becomes;
1 + 1 = 2 .
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
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
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.
Because mod(X) is always a positive value there the first fraction is equal to 1 therefore the answer is 1+1=2
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
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.
the root of x squared is1 , the value of x is 1 so that 1+1=2
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
same as kartik solution . u should refer to graph plotiing of root x^2
As x is a real no. x1/2=|x|
And thus 1+1=2
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
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 :)
2 or 0.
If x>o, the ans is 2. If x<0, the ans is 0.
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
(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
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.
Problem Loading...
Note Loading...
Set Loading...
x 2 = ∣ x ∣ , so ∣ x ∣ x 2 + 1 = 1 + 1 = 2
The common misconception is that 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 1 0 0 = 1 0 , but if we had the equation x 2 = 1 0 0 , then x = ± 1 0 .