TeX джерело:

= \frac{\pi }{2}(x - \frac{1}{2}\sin (2x))|_0^{\frac{\pi }{2}} = \frac{\pi }{2}(\frac{\pi }{2} - \frac{1}{2}\sin \pi ) - \frac{\pi }{2}(0 - \frac{1}{2}\sin 0) = \frac{{{\pi ^2}}}{4}