JEE Advanced2012MathematicsEllipseActual
The ellipse E₁: x² 9 + y² 4 =1 is inscribed in a rectangle R whose sides are parallel to the coordinate axes. Another ellipse E₂ passing through the point (0,4) circumscribes the rectangle R . The eccentricity of the ellipse E₂ is
Options
- A2 2
- B3 2
- C1 2
- D3 4
Correct answer
C. 1 2
Step-by-step solution
As rectangle A B C D circumscribed the ellipse x² 9 + y² 4 =1, A=(3,2) Let the ellipse circumscribing the rectangle A B C D is x² a² + y² b² =1...(i) Given that ellipse (i) passes through (a, 4) b²=16 Also ellipse (i) passes through A(3,2) 9 a² + 4 16 =1 a²=12 e= 1- 12 16 = 1 4 = 1 2