Answer
(a). $f(x) = sec (x) tan (x)$ which is zero when $tan (x) = 0$
(since $sec (x)$ is never zero.) So we are looking for where $\frac{sin (x)}{cos (x)} = 0$, which is when $sin (x) = 0$, which is at $x = 0$.
b. $f(−π/4) =√2 = f(π/4)$ and $f(0) = 1$. So the absolute maximum for $f$ is $√2$ and the absolute minimum is 1.
Work Step by Step
See the graph for explanation.