(a) The gas law for a fixed mass $m$ of an ideal gas at absolute temperature $T,$ pressure $P,$ and volume $V$ is $P V=m R T,$ where $R$ is the gas constant. Show that
$$\frac{\partial P}{\partial V} \frac{\partial V}{\partial T} \frac{\partial T}{\partial P}=-1$$
(b) For the ideal gas of part (a), show that
$$T \frac{\partial P}{\partial T} \frac{\partial V}{\partial T}=m R$$