SOLUTION: Write the equation in standard form for the conic section. An ellipse centered at (3,2) with vertices at (9,2) and (-3,2)and co vertices at (3,5) and (3,-1)

Algebra ->  Quadratic-relations-and-conic-sections -> SOLUTION: Write the equation in standard form for the conic section. An ellipse centered at (3,2) with vertices at (9,2) and (-3,2)and co vertices at (3,5) and (3,-1)      Log On


   



Question 608548: Write the equation in standard form for the conic section.
An ellipse centered at (3,2) with vertices at (9,2) and (-3,2)and co vertices at (3,5) and (3,-1)

Found 2 solutions by solver91311, Edwin McCravy:
Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!


From the coordinates of the center and the vertices/co-vertices, we can see that the center is at (3,2), the semi-major axis measures 6 (because the distance from (3,2) to (9,2) is 6) and the semi-minor axis measures 3 (because the distance from (3,2) to (3,5) is 3). Furthermore the major axis is parallel to the -axis (because the line through (3,2) and (9,2) is horizontal).

The equation of an ellipse centered at with a semi-major axis that measures , a semi-minor axis that measures , and a major axis parallel to the -axis is:



Just plug in the numbers.

John

My calculator said it, I believe it, that settles it
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Answer by Edwin McCravy(20056) About Me  (Show Source):
You can put this solution on YOUR website!
Write the equation in standard form for the conic section.
An ellipse centered at (3,2) with vertices at (9,2) and (-3,2)and co vertices at (3,5) and (3,-1)

I think you need a more graphical approach than just a word explanation.

Plot the points and draw the graph:



Since the ellipse is this way "drawing%2825%2C15%2C-2%2C2%2C-1%2C1%2Carc%28.56%2C0%2C4%2C2%29%29" and not this way "drawing%2815%2C25%2C-1%2C1%2C-2%2C2%2Carc%28.58%2C0%2C2%2C4%29%29", its equation is:

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

[Had it been the other way the "a" and "b" would be switched. In an
ellipse "a" is always larger than "b", but not necessarily in a hyperbola!]

(h,k) = the center = (3,2),  "a" = semi-major-axis, sometimes called
"the long radius" and "b" = the semi-minor-axis, sometimes called
"the short radius".

draw the semi-major and semi-minor axes:
The red line is the semi-major axis and the green line is the semi-minor
axis.



Count the number of units that the red and green lines are in
length and you'll get a = 6 and b = 3.  Therefore the equation

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

becomes:

%28x-3%29%5E2%2F6%5E2 + %28y-2%29%5E2%2F3%5E2 = 1

or

%28x-3%29%5E2%2F36 + %28y-2%29%5E2%2F9 = 1

Edwin