Evaluate ∫0π/4tan2(x)dx\int_{0}^{\pi/4} \tan^2(x) dx∫0π/4tan2(x)dx using the identity tan2(x)=sec2(x)−1\tan^2(x) = \sec^2(x) - 1tan2(x)=sec2(x)−1.
1−π/41 - \pi/41−π/4
π/4−1\pi/4 - 1π/4−1
2−1\sqrt{2} - 12−1
π/2\pi/2π/2