Find the average value of f(x)=sec2(x)f(x) = \sec^2(x)f(x)=sec2(x) on the interval [0,π4][0, \frac{\pi}{4}][0,4π].
111
4π\frac{4}{\pi}π4
π4\frac{\pi}{4}4π
2π\frac{2}{\pi}π2