# Thread: Equation of a n ellipse??

1. ## Equation of a n ellipse??

Find the equation of the ellipse whose foci are (3,0) and (-3,0) and whose sum of focal radii is 10 ???

2. Originally Posted by willy92
Find the equation of the ellipse whose foci are (3,0) and (-3,0) and whose sum of focal radii is 10 ???
First look at Mathwords: Focal Radius

So I will assume your starting point is $\sqrt{(x + 3)^2 + y^2} + \sqrt{(x - 3)^2 + y^2} = 10$.