If anyone could lend some help on these that would be great!

Find the derivative:

1. f(x)=sinx-2tanx

2. y=tan(sinx^2)

3. f(x)= tan^-1 sq.root(1-x)

4. y=(secx+tanx)

5. Let f(x) = 7sin(x+pi)+cos2x

a. compute f'(x), f''(x), f'''(x), f''''(x)

b. compute f*13th derivative*(0)