Question
Question: A tangent to y<sup>2</sup> = 16x is y = 4x + 1. Point on this tangent from which a perpendicular tan...
A tangent to y2 = 16x is y = 4x + 1. Point on this tangent from which a perpendicular tangent can be drawn to same parabola:
A
(– 4, 0)
B
(– 4, – 4)
C
(– 4, –15)
D
None
Answer
(– 4, –15)
Explanation
Solution
Point of intersection of perpendicular tangents lies on
directrix .
Hence resultant point is intersection point of tangent
y = 4x + 1 & directrix x = – 4 ̃ (– 4, – 15)