Let f be the function deﬁned by
f(x) = x − 2 sin(x), 0 ≤ x ≤ π .
On which interval(s) is f increasing?
A. 1/3π, π
B. 0,1/3π ∪ 2/3π, π
C. 0,1/3π
D. 1/6π,5/6π
E. (0, π)

Question

Let f be the function deﬁned by
f(x) = x − 2 sin(x), 0 ≤ x ≤ π .
On which interval(s) is f increasing?
A. 1/3π, π
B. 0,1/3π ∪ 2/3π, π
C. 0,1/3π
D. 1/6π,5/6π
E. (0, π)

anonymous · Answer

A function is increasing where its derivative is positive.

So find f ' (x) and then solve f ' (x) > 0.

anonymous · Answer

@lesliemariahp 

Stillwaiting to see your f ' (x) and how you solve f ' (x) > 0.