Consider the differential form of thermodynamic potentials; Maxwell's equations can be derived from thermodynamics potentials. Internal energy is a function of entropy and volume. Since it is an exact differential, its second-order derivative with respect to volume and entropy does not depend on the order of differentiation. Substituting the expressions of temperature and pressure gives the first Maxwell's relation. Enthalpy depends on entropy and pressure. Taking the second-order derivative and substituting the expressions for temperature and volume gives the second Maxwell's relation. Helmholtz free energy depends on volume and temperature. Expressing it as a second-order derivative and substituting the expressions of pressure and entropy gives the third Maxwell's relation. Gibbs free energy is a function of pressure and temperature. Differentiating it twice and substituting the relations of volume and entropy gives the fourth Maxwell's relation. Maxwell's equations are used to solve complex thermodynamic problems as they relate a partial differential between quantities that are hard to measure experimentally to a partial differential between easily measurable quantities.