- #1

reenmachine

Gold Member

- 513

- 8

## Homework Statement

Suppose ##x## and ##y## are positive real numbers.If ##x < y## , then ##x^2 < y^2##.

## Homework Equations

Assume ##x<y## with ##x,y \in ℝ^+##.This implies that ##\exists z \in ℝ^+## such that ##x+z=y##.We have ##y^2 = (x+z)^2 = x^2 + 2xz + z^2## , and this proves that if ##x < y## with ##x,y \in ℝ^+## , then ##x^2 < y^2##.

any thoughts on that one? Thank you!

Last edited: