EquationTrekker

choose a system of equations:

{Sin[x[t]]+

′

y

[t]0,

′

x

[t]y[t]}

length

This provides an interactive tool for investigating solutions of systems of differential equations. The solutions can be viewed as paths or trajectories. The curves shown ("treks") are the solutions (shown in the y' versus y phase plane) with initial conditions through the locators.