Answer
a.)$\frac{1}{2}$
b.)$\frac{1}{2}$
Work Step by Step
a.)cos $\frac{\pi}{3}$ corresponds to x value.
cos $\frac{\pi}{3}$ = $\frac{1}{2}$
b.)Cosine is an even function, so cos(-t) = cos t.
cos-$\frac{\pi}{3}$ = cos$\frac{\pi}{3}$ = $\frac{1}{2}$
