## anonymous one year ago What are the foci of the following graph?

1. anonymous

2. anonymous

@Hero

3. anonymous

What are the vertices?

4. anonymous

3 and -3?

5. anonymous

that are co-vertex, how about main one?

6. anonymous

5 and -5

7. anonymous

i ment 6 and -6

8. anonymous

ok, it is a vertical ellipse, hence the main one is a, and the co- one is b that is a = 6 and b =3 you have the formula to find foci c, which is $$c^2 = a^2 -b^2$$, hence c =??

9. anonymous

27?

10. anonymous

that is c^2 , not c

11. anonymous

13.5?

12. anonymous

$$\sqrt{27} =??$$

13. anonymous

5.19615

14. anonymous

ok, it is $$3\sqrt3$$ you can take your number.

15. anonymous

One more thing, foci are on the same line with main vertices, right? your main one is $$(0, \pm 6)$$, hence your foci are $$(0,\pm 3\sqrt3)$$ Whenever jot down the foci or the vertex, you MUST write the pair of them to make it clear for the shape of the conic.

16. anonymous

so what the anwser? im sorry..this confuesses me

17. anonymous

@OOOPS

18. anonymous

@Peaches15

19. anonymous

|dw:1439513790413:dw|

20. anonymous

|dw:1439513807160:dw|

21. anonymous

neither of those are a choice

22. anonymous

That is b , they are allllllllllllllll same.

23. anonymous

ohh okay!

24. anonymous

|dw:1439513905893:dw|