» This article describes the use of the term nonlinearity in mathematics. For other meanings, see nonlinearity (disambiguation). In mathematics, a nonlinear system is a system which isn't linear, that is, a system which doesn't satisfy the superposition principle, or whose output isn't proportional to its input. Less technically, a nonlinear system is any problem where the variable(s) to be solved for can't be written as a linear combination of independent components. A nonhomogeneous system, w… (More on Nonlinear)