1. The problem statement, all variables and given/known data ∫(0 to 2) ∫(2x to 4) [e^(-y^2)] dydx This was a question given for a multivariable class exam a couple years ago, and we don't ever learn about the exponential integral in that class. 2. Relevant equations We know how to go about solving this, BUT... 3. The attempt at a solution So everyone knows you can't integrate e^(-y^2) dy directly. So i changed the bounds of integration to get ∫(0 to 4) ∫(y/2 to 2) [e^(-y^2)] dxdy. Doing that, the first integral became xe^(-y^2) from y/2 to 2, which gave me ∫(0 to 4) [2e^(-y^2) - ye^(-y^2)/2] dy So now I'm stuck with the same problem with that first part of the integral. Now what do I do?! Thanks.