1. The problem statement, all variables and given/known data r''-(theta')^2=-g reads: second derivative of r minus the first derivative of theta squared equals negative g 2(r')theta'+(r)theta''=0 reads: 2 times the first derivative of r times the first derivative of theta plus r times the second derivative of theta. both r and theta are a function of time. Oh and the derivatives of each variable are with respect to time. 2. Relevant equations 3. The attempt at a solution I really have no clue as to how I'm going to solve this system of differential equations. I'm trying to solve for r'