Question

If the direction cosines of a line are $\left( \frac{1}{c},\frac{1}{c},\frac{1}{c} \right)$, then

• A. c> 0
• B. $c = \pm \sqrt{3}$
• C. 0 < c < 1
• D. c > 2

Answer 1

Answer: (B)

$c = \pm \sqrt{3}$

Answer 2

Length = $\sqrt{4 + 9 + 36}$ = 7