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.