# Equation with a definite integral - can I differentiate it?

I have an equation like this:

$$te^{t} = \int\nolimits_0^t e^\tau u(\tau)d\tau$$

I don't really know how to solve it.. Would it be possible to differentiate both sides of the equation? If so, how can I do it - is it like differentiate one side and then the other or is it more complex? And if it is possible what conditions need to be satisfied in order to do it?

• Thank you for editing, I didn't really know why this was not rendering properly. Help for MathJax is very poor on this site. Feb 17 '11 at 11:21