The slopes of isothermal and adiabatic curves are related as
Adiabatic curve slope = isothermal curve slope
For Isothermal process PV=constant⇒dPdV=−PV=Slope of Isothermal curveFor adiabaticPVγ=constant⇒dPdV=−γPV=Slope of adiabatic curve slopeClearly,(dPdV)adiabatic=γ(dPdV)Isothermal