Conic Sections Question 153
Question: The centroid of the triangle formed by joining the feet of the normals drawn from any point to the parabola $ y^{2}=4ax $ , lies on
[MP PET 1999]
Options:
A) Axis
B) Directrix
C) Latus rectum
D) Tangent at vertex
Show Answer
Answer:
Correct Answer: A
Solution:
Normal to parabola will be, $ y=mx-2am-am^{3} $
For three values of m. Three normal can be drawn on parabola $ y^{2}=4ax $ . So three feet of normals can be obtained, hence centroid of triangle lies on axis of parabola.
BETA
