Download the app

Questions  

If chords of contact of the tangent from two points 

x1, y1 and x2, y2 to the ellipse x2a2+y2b2=1 are at right angles, then x1x2a2×y1y2b2 is equal to

a
a2b2
b
−b2a2
c
−a4b4
d
b4a4

detailed solution

Correct option is C

Chords of contacts are xx1a2+yy1b2=1 and xx2a2+yy2b2=1Since they are at right angles−b2a2×x2y2×−b2a2×x1y1=−1⇒x1x2y1y2=−a4b4

Talk to our academic expert!

+91

Are you a Sri Chaitanya student?


Similar Questions


phone icon
whats app icon