Multivariable calculus and ideal gas law 2 - cosn = 2/2 cosst. the isothermal compressibility is defined as ky - isothermal means at constant temperature, isothermal compressibility describes how compressible the gas/material is, held at constant temperature. (1) using pv=nrt, calculate the isothermal compressibility of an ideal gas. (5 points) kr = - + 125 pv: nrt v=nrt (2) give a physical explanation of your result. (3 points)