Still looking for this...
The gas law for a fixed mass m for an ideal gas at absolute temperature T, pressure P, and volume V is PV = mRT, where R is the gas constant.
Show that бP/бV бV/бT бT/бP = -1
So basically P = mRT/V, V = mRT/P, T = PV/mR are the different functions, and we take the partial derivative of each...but not totally sure how