Question

If the line $6x-7y+8+\lambda (3x-y+5)=0$ is parallel to y-axis, then $\lambda =$ ______.

• A. $-7$
• B. $-2$
• C. $7$
• D. $2$

Answer 1

The correct option is A $-7$

The line $6x-7y+8+\lambda (3x-y+5)=0$ is parallel to y axis.

Thus, the slope of the line must be infinity, or the coefficient of y must become zero.

$\therefore -7-\lambda =0$

$\therefore \lambda =-7$