Question

The equation of the straight line passing through the point $(3,2)$ and perpendicular to the line $y=x$ is

• A. $x-y=5$
• B. $x+y=5$
• C. $x+y=1$
• D. $x-y=1$

Answer 1

Answer: (B)

Equation of a line perpendicular to $y=x$ is $x+y+\lambda =0$. It passes through $\left(3,2\right)$.
$\therefore 3+2+\lambda =0$
$\Rightarrow \lambda =-5$
$\Rightarrow$ Required equation is $x+y-5=0$