1. The problem statement, all variables and given/known data The problem is stated as Find the force function for a particle subject to a central field for each of the orbits as follows a.) r=roCosθ b.) r=roe^kθ 2. Relevant equations We know the F(x)= dv/dx here I am assuming F(x)=dv/dθ 3. The attempt at a solution Do I just take the derivative of the orbit. I believe so but it must be in a different way. Should I make r=√(x^2+y^2) or simply just take the derivative?