KCET2016MathematicsStraight Lines
If the straight lines ( 2 x+3 y-3=0 ) and ( x+k y+7=0 ) are perpendicular, then the value of ( k ) is
Options
- A( 2 3 )
- B( 3 2 )
- C( - 2 3 )
- D( - 3 2 )
Correct answer
C. ( - 2 3 )
Step-by-step solution
Given lines, [ array l 2 x+3 y-3=0 (1) x+k y+7=0 (2) array ] From Eqs. (1) and (2), we get [ m₁= -2 3 and m₂=- 1 k ] Since, both lines are perpendicular so [ array l m₁ m₂=-1 -2 3 (- 1 k )=-1 2 3 k =-1 k= -2 3 array ]