SOLUTION: Write an equation for the ellipse with vertices (2,2),(4,2),(3,-1), and (3,5).

Algebra ->  Quadratic-relations-and-conic-sections -> SOLUTION: Write an equation for the ellipse with vertices (2,2),(4,2),(3,-1), and (3,5).      Log On


   



Question 968902: Write an equation for the ellipse with vertices (2,2),(4,2),(3,-1), and (3,5).
Answer by Edwin McCravy(20063) About Me  (Show Source):
You can put this solution on YOUR website!
(2,2),(4,2),(3,-1), and (3,5).

Plot the points:



Sketch the ellipse:



It's shaped like the number zero 0, so it has equation:

%28x-h%29%5E2%2Fb%5E2%2B%28y-k%29%5E2%2Fa%5E2=1

Draw the major and minor axes:



The ases cross at the center, which is (h,k) = (3,2)

Counting the units, we see that the major axis is 6, and the semi-major
axis is a = 3, half of 6.

Counting the units, we see that the minor axis is 2, and the semi-minor
axis is b = 1, half of 1.

So we substitute, h=3, k=2, a=3, and b=1 in

%28x-h%29%5E2%2Fb%5E2%2B%28y-k%29%5E2%2Fa%5E2=1

and get

%28x-3%29%5E2%2F1%5E2%2B%28y-2%29%5E2%2F3%5E2=1

%28x-3%29%5E2%2F1%2B%28y-2%29%5E2%2F9=1

Edwin