A question that I have been given asks me to use a certain substitution to find the answer exactly. The only thing is not only do I think I can manage without it the substitution is the most random thing one I've seen.

Upper Boundary = 2, Lower Boundary = 0

Integrate: (4-x)^(1/2).dx

Use the substitution x = 2sin u to exactly evaluate this definite integral.

Should I just do it without using that substitution?