Squaring Any Real

Algebra Level 2

x 2 x \Large x^2 \geq x

For all real numbers x , x, is the above statement true or false?

True False

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21 solutions

Plusle Atreides
Dec 21, 2015

INDIRECT PROOF

x^2 < x

x^2 - x < 0

x(x-1)<0

0<x<1

so, the statement is FALSE when 0<x<1

Justin Eberlein
Dec 26, 2015

Technically neither. A more mathematically accurate way to word it would be "Is this true for all real numbers x?"

True man .

Steven A. Flores Ortiz - 5 years, 5 months ago
Jonathon Wright
Dec 20, 2015

The square of a positive fraction will be less than the original number.

This is my favourite explanation as it is the most succinct. However, you must say "The square of any positive fraction less than one..." I know what you meant, but fractions can be greater than one (e.g. 4/3). A better wording would be: The square of any positive fraction less than one will be less than the fraction itself.

Kyle Smith - 5 years, 5 months ago
Zeeshan Ali
Dec 21, 2015

x 2 x x^{2} \ge x is false for all the Real Numbers x such that 0 < x < 1 0<x<1 and true for all other Real Numbers.

thanks Sir

Michael Kwofie - 5 years, 2 months ago
Piyush Kumar
Dec 20, 2015

Its only true if x is greater than 1

Or less than 0.

Stacey Greenstein - 5 years, 5 months ago
Alfie Chambers
Dec 30, 2015

if x is 0.5 the x2 is 0.25 so x2 is smaller than x

Debmeet Banerjee
Dec 29, 2015

Fractions!!

Ashish Menon
Dec 20, 2015

It is not true for all real numbers less than 1

Nope, the statement is true for all real values less than or equal to 0 0 . It is only false for real numbers 0 < x < 1 0<x<1

Hung Woei Neoh - 5 years ago
Drex Beckman
Dec 16, 2015

0 and 1 squared do not increase

Wrong, the condition states that x 2 x^2 is greater than or equal to x x . For 0 and 1, x 2 x^2 is equal to x x .

Andy Wong - 5 years, 5 months ago

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Yes...you are correct...in this 2 cases the statement is correct...

Saifur Rahman - 5 years, 5 months ago
Dominic Parnell
Feb 28, 2016

If x is defined as a quotient then the numbers' squared product will be less than the number itself. The only definition for x that will make the proposition true is when x is greater than or equal to 1 or less than or equal to 0. Since x^2 must be greater than or equal to x.

Ace Sutton-Smith
Jan 12, 2016

Very obvious. 1/2 * 1/2 is 1/4.

Abhijit Dey
Jan 5, 2016

x^2 is not always greater than or equal to x... It is true only when x=0 or x is any real number greater than or equal to 1. But when 0<x<1, the statement is false. For example, if x=0.5, then x^2=(0.5)^2=0.25 which is less than 0.5

Max Puta
Jan 1, 2016

x^2>or=x divide both sides by x.

x>1

above step is not true for all real numbers.

therefore original statement is false

Daniel Schnoll
Dec 31, 2015

x^2 isn't always >x

.5^2 = .25, and .25 is less than .5

The statement is false for

              0<x<1

Hence the answer is false

Anish Ray
Dec 30, 2015

Given, x^2≥x Or, x^2-x≥0 Or, x(x-1) ≥0 Now,This implies that x ϵ (-∞,0]U[1,∞),i.e,for real numbers between 0 and 1 will not satisfy the given inequality. Thus the answer will be false.

Garoiu Stefan
Dec 27, 2015

x^2-x>=0 then derivation, solution of derivation, then three intervals (-infinite; 0) [0;1/2] (1/2;infinite)

Alexis Reyes
Dec 27, 2015

Or you could do x=1

(1)^2=1

Brian Lee
Dec 27, 2015

If 0<x<1, then x^2 is actually smaller than x. So it is not true for ALL real numbers x.

Elias Peixoto
Dec 27, 2015

It's true if x>1 or if -1>x>0.

Maher Farag
Dec 21, 2015

It will be smaller when X is a fraction number

Only when x is a positive fraction. Negative fractions, indeed any negative number, is less than its square as the square will be positive.

Stacey Greenstein - 5 years, 5 months ago

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Yea ... only false with positive fractions. Other than that it is true.

Andy Taylor - 5 years, 5 months ago

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