What is the integration of [math]\int_{-\pi}^{\pi} x^{2} \cos x \mathrm{d} x[/math]?
How do I calculate the integral of [math]\displaystyle2\int_{-1/2}^{1/2} |\sin (\pi t)|\,\cos (2 \pi n t)\,\mathrm{d}t[/math]?