Question

Finding Ellipse?!?!

Find the equation of the ellipse with the following properties.

The ellipse with x-intercepts at (4, 0) and (-4, 0), y-intercepts at (0, 9) and (0, -9), and center at (0, 0).

Find the equation of the ellipse with the following properties.

The ellipse with x-intercepts at (7, 0) and (-7, 0), y-intercepts at (0, 5) and (0, -5), and center at (0, 0).

Write the equation of the given circle.

center (-2, -2)
radius of 6

How do I do this

Answer 1

Why did you post this again?

Answer 2

I didn't?

Answer 3

For the first one, what is the center?

Answer 4

0,0

Answer 5

So we know that the numerators will be x^2 and y^2

Answer 6

we do?

Answer 7

Is the major axis vertical or horizontal?

Answer 8

vertical I think

Answer 9

Yes we do because we know that the equation of an ellipse is
(x-h)^2/a^2 +(y-k)^2/b^2=1 if the major axis is horizontal and
(x-h)^2/b^2+(y-k)^2?a^2=1 if the major axis is vertical.

Answer 10

So in the first case, h and k are both 0

Answer 11

Since the major axis is vertical, we know that the big number goes under y^2.

Answer 12

wait

Answer 13

And since a is the distance from the center to the end of the major axis, what is the value of a?

Answer 14

write it out here so I can understand all of this better please? http://www.twiddla.com/1470080