Помогите решить 9.3 и 9.14 даю 40 баллов

Решите задачу:

$9.3a)\; \; \int\limits^{\frac{\pi}{2}}_{-\frac{\pi}{2}} {3\cdot cosx} \, dx =3\cdot sinx\Big |_{-\frac{\pi}{2}}^{\frac{\pi}{2}}=\\\\=3\cdot (sin \frac{\pi }{2} -sin(- \frac{\pi }{2} ))=3(1+1)=6\\\\9.3b)\; \; \int\limits^2_0 {(1-\frac{x}{2})^4} \, dx =-2\cdot \frac{(1-\frac{x}{2})^5}{5}\, \Big |_0^2=-\frac{2}{5}\cdot (0^5-1^5)=\frac{2}{5}$

$9.14a)\; \; \int\limits^{\pi }_0 {3sin\frac{x}{2}} \, dx =3\cdot 2\cdot (-cos\frac{x}{2})\Big |_0^{\pi }=\\\\=6\cdot (-cos\frac{\pi}{2}+cos\, 0)=6\cdot (-0+1)=6\\\\9.14b)\; \; \int\limits^0_1 {(1-2x)^4} \, dx =-\frac{1}{2}\cdot \frac{(1-2x)^5}{5} \Big |_1^0=\\\\=-\frac{1}{10}\cdot (1^5-(-1)^5)=-\frac{1}{10}\cdot 2=-\frac{1}{5}=-0,2\\\\\\Formyla:\; \; \; \int (ax+b)^{k}dx=\frac{1}{a}\cdot \frac{(ax+b)^{k+1}}{k+1} +C$