# Central force as a conic: How to show it?

1. Mar 17, 2008

### kthouz

If F denotes the central force and is given as the inverse of the square distance
F=-k/r^2. where k>0. How can i show that F the path of the partilce under that force is a conic?
What i can see is that it is the second law of Kepler. And when i try to compare F with the former equation of conics r= (pe)/(1+ecosB). I can find p!