Question: eval not working for solutions of ODE system

I have to create a function which records the angle and angular frequency of an aspherical moon orbiting a planet at each periapsis to create a Poincare section plot of theta agaisnt omega. I cannot get eval to work out the solutions to the ODEs to plot the points. Additionally I then have to create another function to plot the FFT of the angular frequency from an array. 

This is what I have tried so far:

Maple Worksheet - Error

Failed to load the worksheet /maplenet/convert/ .


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