Differential Equation/Examples/Second Order Non-Linear Ordinary

Example of Differential Equation
Ordinary non-linear differential equation of the $2$nd order
 * $\dfrac {\d^2 y} {\d x^2} + \paren {3 \dfrac {\d y} {\d x} }^3 + 2 x = 7$

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

The term in $\dfrac {\d^2 y} {\d x^2}$ is to the $1$st degree.

Hence the result by definition of degree.