Question

Find direction cosines of line given by $x=ay+b,z=cy+d.$

Answer 1

Line $\to x=ay+b$

$z=cy+d$

$\frac{x-b}{a}=y$

$\frac{z-d}{c}=y$

Line $\to \frac{x-b}{a}=\frac{y}{1}=\frac{z-d}{c}$

Direction cosines $(a,1,c)$.