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August 26th, 2016, 07:26 AM   #1
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HELP ME!! Super confused @~@

Given: 2. An ellipse has vertices (10,-4) and (6,-4), and covertices (-2,-9) and (-2,1). Find its standard equation and its foci.

I graphed it first, but.. (???)

https://scontent.xx.fbcdn.net/v/t34....d7&oe=57C350E4


Someone explain this to me~~ ㅠㅠ
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August 26th, 2016, 07:45 AM   #2
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well clearly there is an error here.

The midpoint of the vertices and co-vertices should coincide.

The midpoint of the major axis is (8,-4)

The midpoint of the minor axis is (-2, -4)

inspection also shows that the minor axis is longer than the major axis which is incorrect by definition.

I'd double check your point values.
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August 26th, 2016, 07:57 AM   #3
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Quote:
Originally Posted by romsek View Post
well clearly there is an error here.

The midpoint of the vertices and co-vertices should coincide.

The midpoint of the major axis is (8,-4)

The midpoint of the minor axis is (-2, -4)

inspection also shows that the minor axis is longer than the major axis which is incorrect by definition.

I'd double check your point values.
So my hunch was right about this.. how about this one?

Given: A hyperbola has vertices (1,9) and (13,9), and one of its foci is (2,9). Find its standard equation.

I graphed it and this is what I got..


Isn't foci supposed to be behind vertex? Is this an error too??
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August 26th, 2016, 08:45 AM   #4
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yep, this makes no sense.

the foci will be at (xwest, 9), (xeast,9)

where xwest < 1, and

xeast > 13
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