SOLUTION: Please help me answer this question? Find an equation for the ellipse that satisfies the given conditions: Foci (1, ±4), vertices (1, ±7)

Algebra ->  Quadratic-relations-and-conic-sections -> SOLUTION: Please help me answer this question? Find an equation for the ellipse that satisfies the given conditions: Foci (1, ±4), vertices (1, ±7)      Log On


   



Question 1048583: Please help me answer this question?
Find an equation for the ellipse that satisfies the given conditions:
Foci (1, ±4), vertices (1, ±7)

Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

Find an equation for the ellipse that satisfies the given conditions:
Foci (1, ±4),
vertices (1, ±7)

The center is midway between the two foci, so (h,+k) = (1, 0), by the Midpoint Formula.
Each focus is 4 units from the center, so c+=+4.
The vertices are 7 units from the center, so a+=+7.
Since the focus and vertex are above and below each other, rather than side by side, I know that this ellipse must be taller than it is wide. Then a%5E2 will go with the y part of the equation.
%28y-k%29%5E2%2Fa%5E2%2B%28x-h%29%5E2%2Fb%5E2+=+1
The equation b%5E2+=+a%5E2+-+c%5E2 gives me
b%5E2+=+7%5E2+-+4%5E2,
b%5E2+=+49+-+16
b%5E2+=+33
and this is all I need to create my equation:
+%28y+-+0%29%5E2+%2F+49+%2B+%28x-1%29%5E2+%2F+33=+1
y+%5E2+%2F+49+%2B+%28x-1%29%5E2+%2F+33=+1