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- Homework Statement
- Conic: r = 15/[3-2cos(theta)]

- Relevant Equations
- conic general form when vertical directrix to left of pole:

r = ed/[1-e*cos(theta)], where d is the distance between focus at pole and the directrix

The text says that the following conic, r = 15/[3-2cos(theta)], can be rearranged to 5/[1-(2/3)cos(theta)]. The graph of the conic is an ellipse with e=2/3.

Then it says that the vertices lie at (15,0) and (3,pi). How did they find the vertices? Thanks.

Then it says that the vertices lie at (15,0) and (3,pi). How did they find the vertices? Thanks.