1.

$\displaystyle

\int \frac{sinx}{cos^3x} dx

$

2. $\displaystyle \int x \sqrt {1-x} dx$

3. if F(x)= $\displaystyle \int_{0}^{\sqrt x} \sqrt {t^2+20} dx

$ find F'(16)

Hi, any help would be wonderful. I really need the explanation more than the answer, though.