Как найти интегралы 1. ʃcos^3(x) / sin^2(x) dx 2. ʃx*sin^2(x^2) dx 3. ʃe^x*cos^2(e^x) dx

$\int{x\cdot sin^2(x^2)}\, dx=\int{x\cdot \frac{1-cos(2x^2)}{2}}\, dx=\frac{1}{2}\int{x(1-cos(2x^2))}\, dx= \\ =\frac{1}{2}\int{(x-xcos(2x^2))}\, dx=\frac{1}{2}(\int{x}\, dx-\int{xcos(2x^2)}\, dx)=\frac{1}{2}\cdot\frac{x^2}{2}- \\ -\frac{1}{2}\cdot\frac{1}{4}\int{cos(2x^2)}\, d(2x^2)=\frac{1}{4}x^2-\frac{1}{8}sin(2x^2)+C,$

$\int{e^x\cdot cos^2(e^x)}\, dx=\int{e^x\cdot \frac{1+cos(2e^x)}{2}}\, dx= \\ =\frac{1}{2}\int{e^x(1+cos(2e^x))}\, dx=\frac{1}{2}\int{(e^x+e^xcos(2e^x))}\, dx= \\ \frac{1}{2}(\int{e^x}\, dx+\int{e^xcos(2e^x)}\, dx)=\frac{1}{2}e^x+\frac{1}{2}\cdot\frac{1}{2}\int{cos(2e^x)}\, d(2e^x)= \\ =\frac{1}{2}e^x+\frac{1}{4}sin(2e^x)+C.$