Помогите срочно надо очень 3 и 5

3)

$\displaystyle \int { \frac{dx}{ \sqrt{2-x^2}} }= \int{ \frac{dx}{ \sqrt{ \frac{1}{2}(1- \frac{x^2}{2})}}}= \int{ \frac{ \sqrt{2} dx}{ \sqrt{1-( \frac{x}{ \sqrt{2}})^2}}}= \sqrt{2}arccos( \frac{x}{ \sqrt{2}})+C$

5)

$\displaystyle \int { \frac{2x^3-5x+8}{3x^2}}= \int{ \frac{2}{3} x}dx- \int { \frac{5}{3x}} \, dx+ \int{ \frac{8}{3x^2}}\, dx =\\= \frac{2}{3} \frac{x^2}{2}- \frac{5}{3}ln|x|+ \frac{8}{3}( -\frac{1}{x})+C= \frac{x^2}{3}- \frac{5}{3}ln|x|- \frac{8}{3x}+C$