# Variational Equation

1. Nov 16, 2011

### urric

Hi, sorry if this isn't the correct forum.
I'm trying freefem++ to solve some some problems with finite elements method, but in the documentation the following form of the variational equation is used:

$\displaystyle\int_{T_{h}} (\frac{{\partial u}}{{\partial x}}\frac{{\partial v}}{{\partial x}} + \frac{{\partial u}}{{\partial y}}\frac{{\partial v}}{{\partial y}} )dxdy =\displaystyle\int_{T_{h}} fvdxdy$

I've searched for that form, but I wasn't able to find it

Could you tell me about a book or any source where I can study that form of the variational equation?

Thanks