JEE Main2013MathematicsEllipseActual
The equation of the circle passing through the foci of the ellipse x 2 1 6 + y 2 9 = 1 , and having centre at 0 , 3 is
Options
- Ax 2 + y 2 - 6 y - 5 = 0
- Bx 2 + y 2 - 6 y + 5 = 0
- Cx 2 + y 2 - 6 y - 7 = 0
- Dx 2 + y 2 - 6 y + 7 = 0
Correct answer
C. x 2 + y 2 - 6 y - 7 = 0
Step-by-step solution
For x 2 1 6 + y 2 9 = 1 a e = 1 6 - 9 = 7 Foci = ± 7 , 0 Radius = 7 + 9 = 4 ∴ Equation of circle = x - 0 2 + y - 3 2 = 4 2 ⇒ x 2 + y 2 - 6 y - 7 = 0