MHT CET202415 May 2024Evening ShiftMathematicsStraight LinesActual
If one of the lines represented by a x^2+2 h x y+b y^2=0 is perpendicular to m x+ n y=18 , then
Options
- Aan ^2+2 hmn + bm ^2=0
- Bam ^2+2 hmn + bn ^2=0
- Cam ^2-2 hmn + bn ^2=0
- Dan ^2-2 hmn + bm ^2=0
Correct answer
B. am ^2+2 hmn + bn ^2=0
Step-by-step solution
Given equation of pair of lines is a x^2+2 ~h x y+ b y^2=0 aligned & a +2 ~h ( y x )+ b ( y x )^2=0 & a +2 hk + bk ^2=0 (i) aligned Now, slope of line m x+n y=18 is -m n Slope of the line perpendicular to m x+ n y=18 is k = n m Substituting the value of k in (i), we get aligned & a+2 h ( n m )+b ( n m )^2=0 & a^2+2 h m n+n^2=0 aligned