Question

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

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

#2 and #2 look the same to me.

note that d(x^2) = 2x dx