So I am doing a few problems for Calculus AB and got stuck on some of the following. I would appreciate it if you could help me and explain how to get the answer. Thanks!

Find dy/dx of the following:

1. y=(2√x)-(1/2√x)

2. y=x/(√1-x^2)

3. y=1/(2sin2x)

4. y=sec^2√x

5. x+cos(x+y)=0