# Thread: simple integration by parts question.

1. ## simple integration by parts question.

Hi

This is something i don't remember what I'm supposed to do. So anyway here goes.

For example if my function was

xe^yx and i wanted to integrate with respect to dx

then i do an integration by parts with these variables:

u = x dv = e^yx

now my question is, when i try to find du do i differentiate with respect to x? same goes for dv, do i integrate with respect to dx?

suppose instead i chose
u = e^yx and dv = x

then du would be ye^yx?

Hopefully that was clear enough.

2. $\displaystyle u=x \ \mbox{and} \ du=dx \ \mbox{and} \ dv=e^{yx} \ \mbox{and} \ v=\frac{e^{yx}}{y}$

Now, solve:

$\displaystyle uv-\int vdu$