Non linear differential equations contain one of more products of
or
terms or maybe powers of these terms or even products of powers. They may look more complicated but they can often be transformed into a simpler form and solved using the one of standard techniques of separation of variables, the integrating factor method or the procedure for solving linear equations.
Example:
(1). Use the transformation
and find the general solution of the resulting equation.
Substitute these into (1)
.
This last equation has complementary solution
and particular solution
hence
so 
and 