Ellipse questions

• Feb 16th 2007, 06:57 PM
gretchen
Ellipse questions
I need a hand at these two problems:

1) How do I find the vertices of the ellipse x[squared]/36 + y[squared]/12=1?

2) How do I find the foci of the ellipse x[squared]/7 + y[squared]/16=1?
• Feb 16th 2007, 07:17 PM
1.) x^2/36 + y^2/12 = 1
Since a^2 = 36 because it is bigger
a= + or - 6

So vertex... SInce it lies on the x-direction: V(+/- a,0)
V_1(6,0)
V_2(-6,0)

2) How do I find the foci of the ellipse x[squared]/7 + y[squared]/16=1
c^2 = a^2 - b^2
c = \squareroot of (16 - 7)
c =\squareroot of 9
c= + or - 3
Foci... Since it lies on the y direction F(0, + or - c)
F_1 = (0, 3)
F_2 = (0,-3)
• Feb 17th 2007, 03:26 PM
ThePerfectHacker
I know this is off topic but it makes me happy seeing you actually learning something at the forum and responding to a thread.
• Feb 18th 2007, 01:24 AM
gretchen
Sorry if you need to have that kind of feedback.

I only post a question for a group of questions I am working on. I take what I learn from the one everyone helps me with and do a number of problems that are similar to it so I get familiar through the practice off-line.

I wish you could only look back at my previous questions and see how far I have actually come.