Question

Which of the following equations represents an ellipse having vertices located at (2,9) and (2,-5) and foci located at (2,5) and (2,-1)?

Answer 1

A.)

Answer 2

B.)

Answer 3

C.)

Answer 4

D.)

Answer 5

one approach, especially if you're like me and never remember the ellipse formulae, would be to take your two known points (the vertices) and try them in each equation.

Answer 6

Oh darn these ellipse >.<

Answer 7

@whpalmer4 what do you mean?

Answer 8

You know the vertices. The center is the midpoint of the major axis. So find the center.

Answer 9

If I'm not mistaken, calculating from the given information the center of the ellipse is (2, 2)

Answer 10

what is the foci?

Answer 11

the vertices are on the ellipse, so if you plug the (x,y) of one of the vertices into the formula and get a nonsense result, like 2 = 3, that isn't the ellipse we're looking for