Non-linear equations
The R-package rootSolve was created by Karline Soetaert mainly for finding the steady-state solutions of differential equations. You will find an example in our differential equations page.
However, it also serves to find the roots of any (set of) non-linear equation(s), or to find multiple roots of one equation.
Here are two examples where functions from the package are used in stability analysis of differential equation models. These examples are taken from the ecological modelling book written by Karline Soetaert and Peter Herman.