# Homework Help: Triangle inequality proof

1. Sep 18, 2008

### pzzldstudent

My professor said this was the triangle inequality. We're to use mathematical induction to prove it. I've gotten some work done, and after "proving" it, it just seems to easy. :|

Last edited by a moderator: May 3, 2017
2. Sep 18, 2008

The work you've done is essentially correct - the idea is to write

$$|a_1 + a_2 + \dots + a_k + a_{k+1}| = |(a_1 + a_2 + \dots + a_k) + a_{k+1}|$$

then use the hint once, then your induction hypothesis.

3. Sep 19, 2008

thank you

thanks!