An ellipse passes through the foci of the hyperbola, 9x^2-4y^2=36 and its major and minor axes lie along the transverse and conjugate axes of the…
JEE Main 2015 — Mathematics Coordinate Geometry
2015mcqmedium
An ellipse passes through the foci of the hyperbola, 9x2−4y2=36 and its major and minor axes lie along the transverse and conjugate axes of the hyperbola respectively. If the product of eccentricities of the two conics is 21, then which of the following points does not lie on the ellipse?
Official previous-year question
Held on 10 Apr 2015 · Verified 6 Jul 2026.
Options
A
(239,3)
B
(213,23)
C
(213,6)
D
(13,0)
Did you get this right?
Sign in to track your attempts and accuracy.
Solution
Equation of the hyperbola
4x2−9y2=1
Focus of hyperbola (a1e1,0) and (−a1e1,0)
a1=2,e1=1+49=213
∴ Foci would be (+13,0) and (−13,0)
Product of eccentricity would be
213⋅e2=21
∴e2=131 .
As the major & minor axis of the ellipse coincide with axis of hyperbola then the value of a2 for ellipse would be 13 ,
e2=1−a22b22
131=1−13b22
b22=12
∴ Equation of the ellipse would be
13x2+12y2=1.
Option (1) 4⋅(13)39+123=1
Satisfies the equation, hence it lies on the ellipse.
Option (2) 4(13)13+4.123=1
does not lie on the ellipse.
Option (3) 2(13)13+126=1 satisfy.
Option (4) 1313+0=1 satisfy.
So, option (213,23) is the answer.
Your note
Sign in to keep a private note on this question. Nothing you write is ever public.