Explanation:
The equation of comet E is given below as

The equation of comet H is modelled below as

Given, that the Sun is located at the origin.
This is an equation of an ellipse. So, the path traveled by Comet e is an elliptic path.
Comparing with the Standard equation of ellipse: below,we will have

Whise center is

By comparing coefficient, we will have

Hence,
The vertex of comet E will be

The vertex of comet E is

Part C:
It is the foci forboth comets

Hence,
The foci will be