# I Need Help On Ellipses Please!

• Jun 6th 2006, 11:52 AM
cutie
I Need Help On Ellipses Please!
ok..so it says to write equation for ellipse that satisfies each set of conditions.
the endpoints of major axis at (3,2) & (3,-14), endpoints of minor axis at (-1,-6) & (7, -6).
HOW DO I DO THIS?
• Jun 6th 2006, 12:52 PM
Soroban
Hello, cutie!

Sorry, I have to ask this: Do you know anything about ellipses?

The general equation of al ellipse is: $\frac{(x - h)^2}{a^2} + \frac{y-k)^2}{b^2}\;=\;1$
. . where $(h,k)$ is the center of the ellipse
. . and $a$ and $b$ are the "x-radius" and "y-radius", respectively.

You have to locate the center, then find $a$ ("half the width")
and $b$ ("half the height") . . . and drop them into the formula.

Quote:

Write equation for ellipse that satisfies each set of conditions:
the endpoints of major axis at (3,2) & (3,-14),
endpoints of minor axis at (-1,-6) & (7, -6).
I don't suppose you tried to make a sketch . . .
Code:

              |               |  (3,2)               |    *     ----------+-----:------------               |0    :               |    :               |    :     (-1,-6) * + - - o - - - * (7,-6)               |    :               |    :               |    :               |    :               |    *               |  3,-14)
Can you see that the center is at $(3,-6)$ . . . and that $a = 4,\;b = 8$?