The Joule-Thomson co-efficient is defined as $${\left( {\frac{{\partial {\text{T}}}}{{\partial {\text{P}}}}} \right)_{\text{H}}}.$$   Its value at the inversion point is

Solution (By Examveda Team)

The inversion point is an point where an sign change occurs so we can define this point as point of inflation. So here the slope (joule thomson cofiicient) is zero hence $${\left( {\frac{{\partial T}}{{\partial P}}} \right)_H} = 0$$