Question
Question: The feet of the normals to y<sup>2</sup> = 4ax drawn from (6a,0) are...
The feet of the normals to y2 = 4ax drawn from (6a,0) are
A
(0,0) (4a, 4a) (4a,-4a)
B
(0,0) (a,2a) (a, -2a)
C
(0,0) (6a, 9a) (6a, -9a)
D
(0, 0) (a, a) (-a, a)
Answer
(0,0) (4a, 4a) (4a,-4a)
Explanation
Solution
The equation of Normal at ‘t’ is y+xt = 2at + at3, this passes through (6a,0).
⇒ 0 + 6at = 2at + at3
⇒ t = 0, 2, -2
∴ The corresponding points are (0, 0) (4a, 4a) (4a,-4a)