Question

Find the center, vertices, and foci of the ellipse with equation

Answer 1

@amistre64

Answer 2

What do you think?

Answer 3

im not sure how to solve this..

Answer 4

we can narrow it down to 2 options by testing the vertexes like the last one

Answer 5

To find the foci, It's c=√(a²-b²)

Answer 6

it is in standard form
center (0,0)
vertices (20,0) and(-20,0)
first find e=sqrt(1-256/400)=12/20
hence focus is((+-20*12/20),0)
so first option

Answer 7

are you sure? @matricked

Answer 8

http://www.wolframalpha.com/input/?i=x%5E2%2F400%2By%5E2%2F256%3D1

Answer 9

Hey matricked, weve been thru this with you before .... OpenStudy policy is:

It is better to guide the user to an answer rather than doing all the work yourself.

We discourage giving out answers without letting the asker at least take some part in the analysis - the aim of this site is to teach.

Please refer to our code of conduct at http://openstudy.com/code-of-conduct for more information. Thank you.

Answer 10

@amistre64 i dont think it is the first option...

Answer 11

im not sure if its the first or not; the verts narrow it down to the first 2 at least

Answer 12

zords property will help narrow it down further

Answer 13

the foci are at sqrt(a^2-b^2) with a^2 being the bigger denominator and b^2 being the other one

Answer 14

@amistre64
sometimes complete ans helps a lot in understanding the probs

Answer 15

well i think it has to be either the 2nd or 3rd option because wolf mentions 16 and 20

Answer 16

it has y verts at 16, and x verts at the 20s; so the options are trying to trick you with the "16"

Answer 17

ohhh.

Answer 18

so, what is 400-256?

Answer 19

144

Answer 20

and sqrt(144) is our foci number

Answer 21

ok

Answer 22

so, you see which option has 20s for our x vert, and 12s for the foci?

Answer 23

A

Answer 24

yep, so matrick .. prolly by shear luck of the draw:) was correct