JEE Main2003MathematicsEllipseActual
The foci of the ellipse x^2 16 + y^2 b^2 =1 and the hyperbola x^2 144 - y^2 81 = 1 25 coincide. Then the value of b^2 is
Options
- A9
- B1
- C5
- D7
Correct answer
D. 7
Step-by-step solution
x^2 144 - y^2 81 = 1 25 a = 144 25 , ~b = 81 25 , e = 1+ 81 144 = 15 12 = 5 4 Foci =(3,0) , focus of ellipse =(3,0) e = 3 4 b^2=16 (1- 9 16 )=7