In mathematics

Mathematics

Mathematics is the study of quantity, space, structure, and change. Mathematicians seek out patterns and formulate new conjectures. Mathematicians resolve the truth or falsity of conjectures by mathematical proofs, which are arguments sufficient to convince other mathematicians of their validity...

, the method of descent is the term coined by the French mathematician Jacques Hadamard

Jacques Hadamard

Jacques Salomon Hadamard FRS was a French mathematician who made major contributions in number theory, complex function theory, differential geometry and partial differential equations.-Biography:...

 as a method for solving a partial differential equation

Partial differential equation

In mathematics, partial differential equations are a type of differential equation, i.e., a relation involving an unknown function of several independent variables and their partial derivatives with respect to those variables...

 in several real or complex variables, by regarding it as the specialisation of an equation in more variables, constant in the extra parameters. This method has been used to solve the wave equation

Wave equation

The wave equation is an important second-order linear partial differential equation for the description of waves – as they occur in physics – such as sound waves, light waves and water waves. It arises in fields like acoustics, electromagnetics, and fluid dynamics...

, the heat equation

Heat equation

The heat equation is an important partial differential equation which describes the distribution of heat in a given region over time...

 and other versions of the Cauchy initial value problem.

As wrote: