Engineering
Mathematics
Normal to Parabola
Question

Let L be a normal to the parabola y2 = 4x. If L passes through the point (9, 6), then L is given by

y + 3x – 33 = 0

y + x – 15 = 0

y – x + 3 = 0

y – 2x + 12 = 0

JEE Advance
College PredictorLive

Know your College Admission Chances Based on your Rank/Percentile, Category and Home State.

Get your JEE Main Personalised Report with Top Predicted Colleges in JoSA

Solution

y = mx – 2m – m3

It passes through (9, 6)

6 = 9m –2m – 2m – m3

m3 – 7m  6 = 0

(m – 1) (m – 2) (m + 3) = 0

  m = –3, 1, 2

Hence equation will be

y = x – 3, y = 2x – 12 and y = –3x + 33