Teaching NVS PGT 2024 Test Series Mathematics Three Dimensional Geometry Direction ratios and Direction cosines
The direction cosines l, m, n of two lines are satisfying 3l + m + 5n = 0 and 6mn − 2nl + 5lm = 0. If θ is the angle between those lines then |cos θ| =
1
\(\frac{1}{\sqrt{6}}\)
2
\(\frac{1}{\sqrt{2}}\)
3
\(\frac{1}{6}\)
4
\(\frac{1}{\sqrt{3}}\)