Tricki
a repository of mathematical know-how

To evaluate an integral, differentiate under the integral sign

Stub iconThis article is a stub.This means that it cannot be considered to contain or lead to any mathematically interesting information.

Quick description

If you have an integral that involves a parameter, then sometimes you can evaluate it by differentiating with respect to that parameter.

This is discussed in some detail in a Wikipedia article on the topic. Eventually it would be nice to have a Tricki article too.