I'm doing a multijoint dynamics problem for a biomechanics class, and I'm using Mathematica to evaluate and solve functions. I have all the equations/variables defined correctly, and they all make sense, and they are all in black text, except for two variables/equations, which are functions for two angles (theta and phi, let's say). Those functions and their derivatives are the only undefined functions in the problem (except for a set of initial conditions).
I'm trying to find expressions for the second derivative of angle theta and . However, when I use the "Solve" or "DSolve" command, I either get a syntax error or an answer that still has the second derivative in it. Obviously, since I'm trying to solve for it, this won't do.
Attached is my code, and I'd appreciate any help you can give, and any errors you can point out in either my coding or my logic.
Thanks for any help. I'm pretty desperate.
Attachment: Code_DerekRoberts_AngularAccelerations.nb, URL: ,