A nonlinear programming
problem (NLP) is an optimization
problem where the objective function or some of the constraints are
nonlinear. Consider the following
problem:

This is an example of an NLP. It is an NLP because of the
multiplication of variables in the objective function. The following
animation describes the features of this problem, as well as the various ways solvers may try to provide a solution.

Press the Start button twice to begin the example.