Answer
$\pi$^{2}
Work Step by Step
Sketch the graph of y=2cos x and y=sec x. By using the washer method, the upper graph needs to be deducted by the lower graph. Using formula \pi \int [f(x)]^{2} - [g(x)]^{2} :
Volume= \pi \int from -\frac{\pi}{4} to \frac{\pi}{4} (2cos x)^{2}-(sec x)^{2}.
