Hyperbola 1 Question 10

11.

A hyperbola, having the transverse axis of length 2sinθ, is confocal with the ellipse 3x2+4y2=12. Then, its equation is

(a) x2cosec2θy2sec2θ=1

(b) x2sec2θy2cosec2θ=1

(c) x2sin2θy2cos2θ=1

(d) x2cos2θy2sin2θ=1

(2007,3M)

Show Answer

Answer:

Correct Answer: 11. (a)

Solution:

  1. The given ellipse is

x24+y23=1a=2,b=3

3=4(1e2)e=12

 So, a=2×12=1

Hence, the eccentricity e1 of the hyperbola is given by

e1=cosecθ[ae=esinθ]

b2=sin2θ(cosec2θ1)=cos2θ

Hence, equation of hyperbola is

x2sin2θy2cos2θ=1 or x2cosec2θy2sec2θ=1.



NCERT Chapter Video Solution

Dual Pane