1. Subsitute remember that
3. Define so that (1)
Now differentiate in (1) using the chain rule and remember that
What are your thoughts?
1. A substitution looks easy enough. u = ???
2. Begging for Integration by Parts if you want to learn something, but a simple substitution of everything under the radical might be a lot easier.
3. A derivative of an integral? Don't forget the Chain Rule. This one likely is ill-formed, Do you mean "dt"?
Let's see what you get.