Question

Determine the trajectories for the nonlinear system, dx/dt = y and dy/dt = x + 13x^3, by integrating the equation for dy/dx

Answer 1

dy/dx = (dy/dt) / (dx/dt)
dy/dx = (x + 13 x^3 ) / y
y dy = (x + 13 x^3 ) dx

∫ y dy = ∫ (x + 13 x^3 ) dx

ok?

Answer 2

yeah, thanks!