Quote by Philip Wood
You've acknowledged my post with the thanks.
P, V and T will be the only variables (for a given number of moles). You should try out the equation I gave you on (a) an ideal gas (b) a V der W gas. Then you'll get a better understanding of how to use it.

So every time when I get the answer I think is correct then I should acknowledge by saying thank? That is all?
[itex]\left(\frac{\partial U}{\partial V}\right)_T = T\left(\frac{\partial P}{\partial T}\right)_{V}  P.[/itex]
For ideal gas I get (∂u/∂v) =RT/(vb) P
Do you mean this?