"If the segment intercepted by the parabola `y=4a x` with the line `l x+m y+n=0` subtends a right
Channel: Doubtnut
Date: 2020-06-28

"If the segment intercepted by the parabola `y=4a x`
 with the line `l x+m y+n=0`
 subtends a right angle at the vertex, then
 `4a l+n=0`
  (b) `4a l+4a m+n=0`
 
 `4a m+n=0`
  (d) `a l+n=0`"