1. The problem statement, all variables and given/known data I have a differential equation that I need to solve numerically by writing a program. x0, y0, x_dot0, y_dot0, α are all given Hello, I have the following differential equation: http://puu.sh/d78KC/107bd6c71f.png [Broken] I want to rewrite it so I can solve it numerically by writing a program. I believe I can replace L2 with m2 * r4 * theta_dot2 making the equation: r_ddot= r*theta_dot2 * sin2 α -g sinαcosα And for the problem to solve numerically, I am given the initial x and y position which I can use to solve r initial. I'm also given the initial x and y velocities, which I could solve the tangential velocity with. I then think I can replace theta_dot2 with v_tan2 /r2 making the equation http://puu.sh/d6pd0/eefb56a511.png [Broken] Does this all work out as I've explained, or did I make an error anywhere? Also, any suggestions on how to write a program to solve this numerically?