I'm using the bead on a wire worksheet by Peter Stone here http://www.peterstone.name/Maplepgs/numDE2.html the mech2RK worksheet.
I've changed the function to a series expansion of sin for an approximation which gives a more interesting curve. But I run into a problem when I set the initial conditions D(x)(0)=-5. If I set D(x)(0)=-4 the bead more or less falls back along the curve but when set as -5 the animation of the bead continues in the wrong direction.
Here is my worksheet.