Calculate ∫0π/2sinnxsinnx+cosnxdx\int_0^{\pi/2} \frac{\sin^n x}{\sin^n x + \cos^n x} dx∫0π/2sinnx+cosnxsinnxdx.
π2\frac{\pi}{2}2π
π4\frac{\pi}{4}4π
πn\frac{\pi}{n}nπ
111