How do you write an ellipse equation with a foci (-10,0) (10,0) and co vertices (0,-3) (0,3)? A.x^2/109+y^2/9=1 B.X^2/109-Y^2/9=1 C.x^2/100+y^2/9=1 D.x^2/100-y^2/9=1

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directrix · Answer

@Karina1   If this is it, I have to study a bit.

anonymous · Answer

yes just this.

directrix · Answer

Which general formula for an ellipse are you supposed to use?

anonymous · Answer

the horizontal or vertical axis which is x^2a+y^2/b=1 or x^2/b+y^2/a/ but not sure which one to plug into

anonymous · Answer

@Directrix

directrix · Answer

The major axis is the segment that contains both foci and has its endpoints on the ellipse. These endpoints are called the vertices. The midpoint of major axis is the center of the ellipse. The minor axis is perpendicular to the major axis at the center, and the endpoints of the minor axis are called co-vertices. The vertices are at the intersection of the major axis and the ellipse. The co-vertices are at the intersection of the minor axis and the ellipse. http://www.mathwarehouse.com/ellipse/equation-of-ellipse.php ------------------ In your options, you can delete B and D because of the presence of the minus symbol. That leaves options A and C for consideration. ------------------------------- Take a look at these Khan Academy videos on ellipses: http://www.khanacademy.org/math/algebra/conic-sections/conic_ellipses/v/conic-sections--intro-to-ellipses

anonymous · Answer

thanks

directrix · Answer

You are welcome.