increasing and decreasing functions

Apr 2010
53
0
For the function f(x)=sin(x)+cos(x) on the interval (0, 2pi) I am supposed to find where f(x) is increasing or decreasing. I took the derivative of the function and came up with f'(x) = cos(x)-sin(x) which i set equal to zero, what do I need to do next?
 

Prove It

MHF Helper
Aug 2008
12,883
4,999
For the function f(x)=sin(x)+cos(x) on the interval (0, 2pi) I am supposed to find where f(x) is increasing or decreasing. I took the derivative of the function, what do I need to do next?
It's increasing when \(\displaystyle f'(x) > 0\) and decreasing when \(\displaystyle f'(x) < 0\).
 

HallsofIvy

MHF Helper
Apr 2005
20,249
7,909
Do that and then use what Prove It said.