A mass m orbits around a planet of mass M in a parabolic orbit of the form y = x^2/(4L), which has focal length L. Find the angular momentum in 3 different ways:
a) Find the speed at closest approach.
b) Use k = (L^2)/(ma)
c) Consider the point (x, (x^2/4L)), where x is very large. Find approximate expressions for the speed and impact parameter at this point.