f(x) = 3 sin x + 3 cos x, 0 ≤ x ≤ 2π
(a) Find the interval on which f is increasing. (Enter your answer using interval notation.)

Question

f(x) = 3 sin x + 3 cos x,    0 ≤ x ≤ 2π
(a) Find the interval on which f is increasing. (Enter your answer using interval notation.)

anonymous · Answer

i honestly have no clue how to do this i took the derivative  3cosx-3sinx but then i'm lost i figured you add 3sinx to the other side 3cosx=3sinx but then what? only time cos=sin is at pie/4

anonymous · Answer

If f is increasing, the derivative has a positive value.

so the question is, from x=0 to x=2π, where do we get
positive values from the function:
   f'(x) = 3cosx - 3sinx

I am not sure which method should be used to find the interval?
you could graph the function..