Integral equation

If the unknown function occurs both inside and outside of the integral, the equation is known as a Fredholm equation of the second type,

One method to solve numerically requires discretizing variables and replacing integral by a quadrature rule

Integral equations are classified according to three different dichotomies, creating eight different kinds:

In general, Volterra and Fredholm integral equations can arise from a single differential equation, depending on which sort of conditions are applied at the boundary of the domain of its solution.