1. The problem statement, all variables and given/known data It is well known that for a conservative motion there is a potential. This potential is a function of coordinates only. Prove this. 2. Relevant equations 3. The attempt at a solution I think you have to take a definition of conservative motion then for example prove that for such a motion, the rotational forces equals to 0 and they don't depend on time, then it will mean that there is a potential field. What is the equation for conservative motion?