The direction cosine of the line \(\rm \frac {x - 5}{6} = \frac {y - 7}{2} = \frac {z - 12} {-3}\) are
1
\(\rm \pm{6 \over7}. \pm{2 \over 7}. \pm{3 \over 7}\)
2
\(\rm \mp{6 \over7}. \mp{2 \over 7}. \mp{3 \over 7}\)
3
\(\rm {6 \over7}. -{2 \over 7}. - {3 \over 7}\)
4
\(\pm {6 \over7}. \pm{2 \over 7}. \mp {3 \over 7}\)