How do you write an equation of an ellipse given the endpoints of major axis at (10,2) and (-8,2), foci at (6,2) and (-4,2)?

1 Answer
Oct 28, 2016

The equation is ((x-1)^2)/81+((y-2)^2)/56=1

Explanation:

We have here a horitontal major axis:
The center is ((10-8)/2,2)=(1,2)
the major axis is a=10-1=9
The distance focus to center is 5
So we can calculate b from b^2=a^2-c^2
b^2=81-25=56

The equation of the ellipseis (x-h)^2/a^2+(y-k)^2/b^2=1

here (h,k)=()1,2 and a=9 And b=sqrt56

So the equation is ((x-1)^2)/81+((y-2)^2)/56=1