By introducing new variables X = f (ε) and Y = f
, (2.3) changes into a system of ODEs as the following form
Now, the Division Theorem which is based on ring theory of commutative algebra, is adopted to obtain one first
integral to (2.4), which reduces (2.3) to a first-order integrable ordinary differential equation. Finally, an exact solution to
(2.1) is established, through solving the resulting first-order integrable differential equation.