http://euler.vaniercollege.qc.ca/web...fc203244b1.png

First off, the limits of integration are both infinites, and I've only worked with one so far, with the other being a number. What changes?

And finally, the exponent within the exponent of e throws me off. There's a way to integrate that entire thing using substitution, but I'm not sure how. Can anyone tell me or at least link me to some tutorial online that explains it?