Non-autonomous system
This example demonstrates the behaviour of a non-autonomous system of ODEs
\[\begin{align*}
f_1(t,x,y)=&\dot x(t) = y\\
f_2(t,x,y) = & \dot y(t) = x-x^3-\frac14 y-A\sin(t)\end{align*}\]
with \(A\in\mathbb{R}\).
Example taken from Voit (2017)