This is bound to come up for me in the next few days because it's one of the favorite tricks of physicsists. Legend has it that when Landau[1], (a legendary Russian physicist and one of my favorite authors), interviewed a new student he gave them seven problem that involved integration by parts. If they couldn't do the problems, they were out. There's a problem though. As you might have guessed from the xkcd funny strip[2], (picture 2), the elegance and power of the technique can serve to obfuscate a student's understanding of it, (as we often say at black-tie physics education soirees). To it more simply, I was never able to memorize or use integration by parts until I realized it can be built from the product rule of integration. Watch:

There are more pointers on how to use the formula once you have it. Basically, you've got a hammer where you're looking for an integral that's the product of a easily recognizable derivative and something else. More on how to make better use of the technique later.

**References:**

1. Wikipedia on Landau

http://en.wikipedia.org/wiki/Lev_Landau

**2. xkcd on integration by parts**

http://xkcd.com/1201/

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