Question

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

Answer 1

I think it's D- none of these

Answer 2

How do you int. C then?

Answer 3

what?

Answer 4

Consider \[ \int\limits{ }{ } x^2e^{x^2} dx.\] If you let u = x^2, then du = 2x dx, and with horrible notation \[\int\limits{}{} xe^u du. \] which is a problem.