If the sum of the slopes of the lines given by `4x^2+2lambdaxy-7y^2=0` is equal to the product of the slope, then `lambda` is equal to

Options

A. `-4`
B. 4
C. `-2`
D. 2

Answer

C

Explanation

Let `y_(1)=m_(1)x` and `y=m_(2)x` be the lines given by `4x^(2)+2kxy-7y^(2)=0`. Then,
`m_(1)+m_(2)=(-2k)/(-7)=(2k)/(7) and m_(1)m_(2)=(-4)/(7)`
It is given that
`m_(1)+m_(2)=m_(1)m_(2)rArr (2k)/(7)=(-4)/(7)rArr k=-2`