Periodic Orbits. Show that the following system has a nonconstant periodic trajectory. \[ \begin {cases} \dfrac {dx}{dt}=\bigl [3-\sin (x^2+y^2)\bigr ]y,\\ \dfrac {dy}{dt}=-3x+\cos (x^2+y^2)y. \end {cases} \]
Question
Math 6410 • ODE
Fall 2003 • Question 3