Conic Sections Question 33

Question: The equations of the tangents of the ellipse $ 9x^{2}+16y^{2}=144 $ which passes through the point (2, 3) is

[MP PET 1996]

Options:

A) $ y=3,\ x+y=5 $

B) $ y=-3,\ x-y=5 $

C) $ y=4,\ x+y=3 $

D) $ y=-4,\ x-y=3 $

Show Answer

Answer:

Correct Answer: A

Solution:

The tangent will be $ y-3=m(x-2) $

therefore $ y-mx=3-2m. $

But it is tangent to the given ellipse, therefore $ m=0,-1 $ .

Hence tangents are $ y=3 $ and $ x+y=5 $ .