[(e^x+e^-x)^2 -(e^x-e^-x)^2]/(e^x+e^-x)^2 simplify and fin the inverse of the simplified equation

[(e^x+e^-x)^2 -(e^x-e^-x)^2]/(e^x+e^-x)^2 simplify and fin the inverse of the simplified equation