Differential Equation/Examples/Third Order Second Degree Non-Linear Ordinary

Example of Differential Equation
Ordinary non-linear differential equation of the $3$rd order and $2$nd degree:
 * $\paren {\dfrac {\d^3 y} {\d x^3} }^2 + \paren {\dfrac {\d^2 y} {\d x^2} }^4 + \dfrac {\d y} {\d x} = x$

Proof
The term in $\dfrac {\d^3 y} {\d x^3}$ is raised to the $3$nd degree and so the equation is non-linear.

The result follows by definition of degree.