Question

Picture included, help with calc?

Answer 1

f is increasing when f ' > 0

Answer 2

Oh I was plugging in without the -1/3 was using 1/3 thanks :D

Answer 3

I'm still getting it wrong actually. Idk

Answer 4

I get (0,6)U(6,inf) for increasing and (-inf,0) for decreasing.

Answer 5

@perl When you get the chance could you try to help me a little more on this one? Much appreciated! Probably just another dumb error. :-(