Perturbation techniques

Abstract

When we model any physical problems to mathematical form, the governing equations may be linear, nonlinear and nonlinear boundary conditions in complex for known and unknown boundaries. The exact solution of those equations may or may not be obtain. Those equations are not solving for an exact solution then their solutions are approximated by using some techniques namely numerical techniques, analytic techniques, and combinations of both. Foremost among the analytic techniques are the systematic methods of perturbations in terms of a small or a large parameter or co-ordinate. These are called perturbation technique.