Suppose a tub has the shape of an elliptical paraboloid given byz=ax^2+by^2 (whe

Suppose a tub has the shape of an elliptical paraboloid given byz=ax^2+by^2 (where ab are some positive constants). If a marblewere released at point (11a+b) on the inside of the tub in whatdirection would it begin to roll. Answer should be a unit vector inthe requested direction.