- #1

- 533

- 1

## Main Question or Discussion Point

I should know how to do this, but I just can't figure it out. Should be a piece of cake. How do you prove, for [itex]x,y\in \mathbb{R}^n[/itex]:

[tex]

\left| (||x|| - ||y||) \right| \leq ||x-y||

[/tex]

[tex]

\left| (||x|| - ||y||) \right| \leq ||x-y||

[/tex]