Hi. I need to figure out how to convert the polar equation

to cartesian coordinates and then graph the resulting equation.

I know it's an ellipse and I know , and , but I can't quite figure out how to make this equation into the standard form for an ellipse. The closest I've come is , which doesn't make any sense. Could someone help me? (Also, I wasn't sure whether this belonged in the calculus or geometry forum, but it's for my calc class so I posted it here.)