Q. The equation of a line passing through $( - 2,\ - 4)$ and perpendicular to the line $3x - y + 5 = 0$ is
A) $3y + x - 8 = 0$
B) $3x + y + 6 = 0$
C) $x + 3y + 14 = 0$
D) None of these
Explanation
(c)
The equation of line perpendicular to line
$3x - y + 5 = 0$ is $x + 3y + \lambda = 0$ …(i)
Also it passes through $( - 2,\ - 4)$.
$\therefore\ - 2 - 12 + \lambda = 0$
$\Rightarrow \ \lambda = 14$
$\therefore$ Required equation of line is
$x + 3y + 14 = 0$[from Eq. (i)]
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.