SOLUTION: My question is: Write the equation for the ellipse whose center is the origin, has a horizontal major axis length of 12 and passses through the point (-4,2). I need help with thi

Question 147808: My question is: Write the equation for the ellipse whose center is the origin, has a horizontal major axis length of 12 and passses through the point (-4,2).
I need help with this, since the horizontal axis is at the origin I get that the foci is (-6,0) and (6,0). I find that the equation will be but I am having trouble finding what equals. Can you help me?
Found 2 solutions by scott8148, Edwin McCravy:
Answer by scott8148(6628) (Show Source): You can put this solution on YOUR website!
substituting the coordinates of the point __ (16/36)+(4/(b^2))=1

subtracting 16/36 __ 4/(b^2)=20/36 __ "cross" multiplying __ 144=20b^2

dividing by 20 __ 36/5=b^2
Answer by Edwin McCravy(20056) (Show Source): You can put this solution on YOUR website!
SOLUTION BY EDWIN
My question is: Write the equation for the ellipse whose center is the origin, has a horizontal major axis length of 12 and passses through the point (-4,2).
I need help with this, since the horizontal axis is at the origin I get that the foci is (-6,0) and (6,0). I find that the equation will be but I am having trouble finding what equals. Can you help me?
Go back and look at the problem to see what if anything you haven't used. Here's what you haven't used:
>>...passses through the point (-4,2)...<<
So you see that all you need do is plug the point (-4,2) into
and solve for b.

Clear of fractions by multiplying thru by

That's an ugly answer, but it is correct. So
the equation of the ellipse in standard form is

Here is its graph:

But if you don't necessarily have to have it in standard
form, you can simplify it.

Multiply top and bottom of the second fraction by

Then multiply through by

Edwin

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