The slopes of isothermal and adiabatic curves are related as:
Isothermal curve slope = Adiabatic curve slope
Isothermal curve slope =γ× Adiabatic curve slope
Adiabatic curve slope =γ× Isothermal curve slope
Adiabatic curve slope =12× Isothermal curve slope
For isothermal process ∆p∆v=-pv
For an adiabatic change ∆p∆v=-γpv
so slope of adia curve = γ slope of isothermal curve