Question

If the line $(2x+y+1)+\lambda (x-y+1)=0$ is parallel to $y-axis$ then value of $\lambda$ is ?

• A. $1$
• B. $-1$
• C. $\frac{1}{2}$
• D. $2$

Answer 1

The correct option is A $1$

Parallel to y-axis $\Rightarrow y=0$

$2x+y+1+\lambda x-\lambda y+\lambda =0$

$x(2+\lambda )+y(1-\lambda )+(1+\lambda )=0$

coefficient of $y=0$

$1-\lambda =0\Rightarrow \lambda =1$