Question

Find an equation of the ellipse having the given points as foci and the given sum of the focal radii

(-9, 0); (9, 0); 30

Answer 1

can you figure out the parts of: a,b,c from this drawing?

Answer 2

since the midpoint between the foci is the center, is 0,0 the equation relates to
\[\frac{x^2}{a^2}+\frac{y^2}{b^2}=1\]
c = distance from center to a focus

Answer 3

thanks :)