Answer
(a) local maximum at $x=0$; local maximum value is $1$
(b) local minimum at $x=-\pi,\pi$; local minimum value is $-1$
Work Step by Step
Based on the give graph:
(a) The number at which f has a local maximum is $x=0$ and the local maximum value is $1$.
(b) The numbers at which f has a local minimum are $x=-\pi,\pi$ and the local minimum values are $-1,-1$.
