Question

The direction ratio of the lines x = ay + b, z = cy + d are:

Answer 1

Direction ratio of line

$x-cy=b$ is

$\frac{1}{\sqrt{1^2+a^2}},\frac{-a}{\sqrt{c^2+a^2}}=\left[\frac{1}{\sqrt{a^2+1}},\frac{-a}{\sqrt{c^2+1}}\right]$

and d.r.s. of line $z-cy=d$

$\left[0,\frac{-c}{\sqrt{1+c^2}},\frac{1}{\sqrt{1+c^2}}\right]$