The Student Room Group
Reply 1
INT (sinx)/x .dx
ex2dx\int e^{-x^{2}}dx
Reply 3
errr...other than ones like e-x2, stuff like etan xsec2x are difficult.

essentially, you want ones involving a product between ef(x) and some function which won't differentiate to itself. (that eliminates sin and cos, the exponential products of which can be integrated by complex numbers/reduction formulae.)
^ You mean practically all ef(x)e^{f(x)} since very very VERY few f(x)'s satisfy your conditions.