An ideal gas is characterised by the relation pV = NRT where p is the pressure of the gas, V is the volume, T is the temperature, N is the number of moles of gas and R is a constant.
a) Calculate the differential dp (T, V).
b) Calculate \frac{\partial }{\partial T} \Bigl(\frac{\partial p(T,V)}{\partial V }\Bigr) and \frac{\partial }{\partial V} \Bigl(\frac{\partial p(T,V)}{\partial T}\Bigr).