SOLUTION: Write An equation for each ellipse. Foci at (-3, -3), (7, -3); the point (2, -7) on ellipse

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Question 1121776: Write An equation for each ellipse.
Foci at (-3, -3), (7, -3); the point (2, -7) on ellipse
Answer by greenestamps(13200) About Me  (Show Source):
You can put this solution on YOUR website!


a = length of semi-major axis
b = length of semi-minor axis
c = distance from center to each focus

The two foci are (-3,-3) and (7,-3); that means the center is (2,-3); that makes c=5.

The point (2,-7) is on the ellipse; it has the same x coordinate as the center; that makes b=4.

For an ellipse, c%5E2+=+a%5E2-b%5E2, or a%5E2+=+c%5E2%2Bb%5E2. You know b and c, so you can determine a.

Now you know a, b, and the center of the ellipse. Plug them into the standard form of the equation.