Question

Please help! Points A and B are the foci of a conic section. Two points on the conic section, C and D, have distances to the foci A and B as shown.
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CA=5
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CB=10
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DA=8
In order for the points C and D to be on the same ellipse, the distance would have to equal what?

Answer 1

the "distance" of what?

Answer 2

Thought we had this one already..

Answer 3

its like a recurrsion equation; just keeps coming back around to haunt you :)

Answer 4

Oh, repost, nobody answered.

Answer 5

:-)

Answer 6

the question is incomplete ....

Answer 7

So, it's just any old conic section then....

Answer 8

"...be on the same ellipse..."

Answer 9

Yes, I saw that after, thinking...

Answer 10

I think he must be referring to the fact that u can create an ellipse with a piece of string and a couple drawing pins at the foci.

ie Ca +Cb = Da +Db making Db = 3 (the missing distance).