SOLUTION: 1. Find focus & directrix (c,0) & x=-c? 2. foci of ellipse are on center (0,0) and y-axis. Draw ellipse, length of major axis is 20 and length of minor axis is 6. How would I

Algebra ->  Quadratic-relations-and-conic-sections -> SOLUTION: 1. Find focus & directrix (c,0) & x=-c? 2. foci of ellipse are on center (0,0) and y-axis. Draw ellipse, length of major axis is 20 and length of minor axis is 6. How would I      Log On


   

Question 949780: 1. Find focus & directrix
(c,0) & x=-c?

2. foci of ellipse are on center (0,0) and y-axis. Draw ellipse, length of major axis is 20 and length of minor axis is 6. How would I get the needed information to be able to graph this?
Thank you
Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
#2 .
You can pick any point for center on the y axis you want.
Taking standard form,
%28x-s%29%5E2%2Fb%5E2%2B%28y-k%29%5E2%2Fa%5E2=1

%28x-s%29%5E2%2F6%5E2%2B%28y-k%29%5E2%2F20%5E2=1
The center IS ON the y-axis, so s=0.
highlight%28x%5E2%2F6%5E2%2B%28y-k%29%5E2%2F20%5E2=1%29

If you are trying to say that the center IS THE ORIGIN, (0,0), the you have
highlight%28highlight%28x%5E2%2F6%5E2%2B%28y%29%5E2%2F20%5E2=1%29%29.
This should be understandable enough for you to draw the graph.


#1:

Simplify this, which is according to the definition for a parabola:
sqrt%28%28x-c%29%5E2%2B%28y-0%29%5E2%29=sqrt%28%28x-%28-c%29%29%5E2%2B%28y-y%29%5E2%29