NTA Abhyas JEE Main2020MathematicsEllipsePractice
Two lines L 1 and L 2 of slope 1 are tangent to y 2 = 4 x and x 2 + 2 y 2 = 4 respectively, such that the distance d units between L 1 and L 2 is minimum, then the value of d is equal to
Options
- A3 - 1 2
- B3 + 1 2
- C2 - 1
- D3 + 2
Correct answer
A. 3 - 1 2
Step-by-step solution
y = x + 1 is a tangent to y 2 = 4 x y = x ± 4 + 2 is a tangent to x 2 4 + y 2 2 = 1 ⇒ Minimum distance will be between the parallel lines y = x + 6 and y = x + 1 ⇒ d = 6 - 1 2 = 3 - 1 2 units