I'm trying to make a 3d animation whose coordinates depends on \[Theta] and \[Phi].
\[Theta] can be numerically solved from an ODE, and the derivative of \[Phi] is related with \[Theta] by another equation.
I'm trying to solve both equations simultaneously with NDSOLVE, but it's not working. (it may be for many reasons)
Is there a way to solve \[Theta] first and then use the result to find \[Phi]?