Question

Let f be differentiable on an open interval I. Prove that If f`(x)=0 for all x in I, then f(x) is constant on I.

Answer 1

do you know how to do it?

Answer 2

Oh sorry spaced out ermmmmm.... no. Rings a tiny bell, but sorry no. :/

Answer 3

I was on a different tab sorry if you were waiting for my answer! :P

Answer 4

ok ` no problem