Question

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Answer 1

Do you know the formula for the eccentricity of an ellipse?

Answer 2

Yes, but in this case, do you know both a and b??

Answer 3

you'll have a hard time memorizing the formula if you don't know each letter means.

Eccentricity will denoted by e, which will be equals to the ratio of two distances. In other words,
e = (first distance) / (second distance)

do you know what those distances are?

Answer 4

excellent! what about a the second one?

Answer 5

very good. Where is the vertex though?

Answer 6

no

Answer 7

There would be no right triangle if that's the case

Answer 8

right. Either top or bottom

Answer 9

see that right triangle? That's how you know where the verteces are