Question

$ox,oy$ are positive $x$-axis, positive $y$-axis respectively where $O=(0,0,0)$ . The $d.c.$s of the llne which bisects $\angle xoy$ are

• A. $1,1,0$
• B. $\frac{1}{\sqrt{2}},\frac{1}{\sqrt{2}},0$
• C. $\frac{1}{\sqrt{2}},0,\frac{1}{\sqrt{2}}$
• D. $0,0,1$

Answer 1

The correct option is B $\frac{1}{\sqrt{2}},\frac{1}{\sqrt{2}},0$

Equation of line bisecting $XOY$ is $x=y$
Therefore, d.r. s are $(1,1,0)$
And thus d.c. s are $(\frac{1}{\sqrt{2}},\frac{1}{\sqrt{2}},0)$
Ans: B