99 Percentile Qs Bank for JEE MainMathematicsHyperbola
A normal to the hyperbola x 2 a 2 - y 2 b 2 =   1 meets the axis in A and B the line A L and B L are drawn at Right angle to the axis and meet at L then locus of L is -
Options
- Aa 2 x 2 - b 2 y 2 = a 2 + b 2 2
- Bb 2 x 2 - a 2 y 2 = a 2 + b 2 2 b
- C4 a 2 x 2 - b 2 y 2 = a 2 + b 2 2
- DNone of these
Correct answer
A. a 2 x 2 - b 2 y 2 = a 2 + b 2 2
Step-by-step solution
Normal to the hyperbola is a x cos θ + b y cot θ = a 2 + b 2 Putting y = 0 and x = 0 We get A a 2 + b 2 a sec θ , 0 , B 0 , a 2 + b 2 b tan θ line through A , perpendicular to the x -axis is x = a 2 + b 2 a sec θ line through B , perpendicular to the y -axis is y = a 2 + b 2 b tan θ So intersection of these point is L ∵ sec 2 θ - tan 2 θ = 1 ⇒ a 2 x 2 - b 2 y 2 = a 2 + b 2 2 .