Question
Mathematics Question on Parabola
If 2x+3y+12=0 and x−y+4λ=0 are conjugate with respect to the parabola y2=8x, then λ is equal to
A
2
B
-2
C
3
D
-3
Answer
-3
Explanation
Solution
If 2x+3y+12=0 and x−y+4λ=0
are conjugate with respect to parabola y2=8x then λ is equal to :
11x+m1y+n1=0
l2x+m2y+n2=0
Are conjugate with respect to parabola y2=4ax
lln2+l2n1=2am1m2
8λ+12=−12
λ=−3