## anonymous 3 years ago Which of the following correctly represents the coordinates of the foci of the ellipse attached?

1. anonymous

2. anonymous

answer choices A,B,C,D from top to bottom :) ***idk :( please explain! THanks :D

3. Hero

There's a great tutorial on this at purplemath.com

4. anonymous

could you please explain this to me? :)

5. Hero

I'm not very good at explaining things.

6. anonymous

so im not quite sure... but I'm thinking B or D right? :/

7. anonymous

aww :( okay :/ but is it B or D? thats what i have simplified it down to so far...

8. Hero

You sound like you're guessing.

9. anonymous

no I'm not cuz i remember a little bit... i got this: The denominator to y is 36, which is > than denominator of x which is 9... so its vertical right?? so you list the y first?? like this?? (y-4)^2/36 + (x+2)^2/9=1... idk am i on the right track so far??

10. anonymous

does that look right to you so far??

11. Hero

I thought that was a minus, it's a plus, so yes, it will be either B or D.

12. anonymous

kk :) so what i did so far is right? :D

13. Hero

At first, I thought it was $\frac{(x+2)^2}{9} - \frac{(y-4)^2}{36} = 1$

14. anonymous

and the center is (-2, 4) right?? which leads me to either B or D... but idk how to find that last part :(

15. anonymous

ohhh hhaa yeah its + :)

16. Hero

I looked at it wrong

17. anonymous

haha yeah its all good =D

18. Hero

If you made it this far, you should be able to figure out which one it is between the two. I told you that you need to be more confident in your work rather than ask for confirmation every time you worked out a problem. When I was your age, I never asked for confirmation. I was always confident in my work.

19. Hero

I didn't use calculators either. I couldn't afford one when I was in HS.

20. anonymous

oh yeah i just don't know what to do after that.. :(

21. anonymous

can you please show me what to do from there?? idk what to do :(

22. Hero

I told you to review the tutorial on purplemath.com

23. anonymous

i don't know where to find it though .... :( can u pls show me what to do from here?? :)

24. anonymous

k so i found this link... http://www.purplemath.com/modules/ellipse2.htm is that it?? I'm reading on it and from that i think the answer is B.... is that it?? am i understanding that link correctly?? is it B?? :D @hero? :)

25. Hero

As I stated before, you should be more confident in your own work. I believe you're smart enough to understand this without having to constant beg me for confirmation.

26. anonymous

okay... well i didn't know this one :( could u pls tell me if i got it right?? =)

27. anonymous

but the tutorial helped a bit... did i get it?? is it B? :O

28. Hero

I'm not going to answer that question.

29. anonymous

okay :) thanks for your help though @Hero!! :) It's much appreciated :)