Which of the following integrals cannot be evaluated using a simple substitution?

Question

the integral of the square root of the quantity x minus 1, dx
the integral of the quotient of 1 and the square root of the quantity 1 minus x squared, dx
the integral of the quotient of 1 and the square root of the quantity 1 minus x squared, dx
the integral of x times the square root of the quantity x squared minus 1, dx

Answer 1

I could easily integrate #1 and #4

I see no difference isn #2 and #3, but would have difficulty with that one.