engineering recuitment NPCIL Plant Operator Mock Test Mathematics Three Dimensional Geometry Direction ratios and Direction cosines
If a line has the direction ratios (1, 2, 3) then its direction cosines are
1
\( \left( {\frac{{ 1}}{{\sqrt {14} }},\frac{{-2}}{{\sqrt {14} }},\frac{{ 3}}{{\sqrt {14} }}} \right)\)
2
\( \left( {\frac{{ 1}}{{\sqrt {14} }},\frac{{2}}{{\sqrt {14} }},\frac{{ 3}}{{\sqrt {14} }}} \right)\)
3
\( \left( {\frac{{ 1}}{{\sqrt {13} }},\frac{{2}}{{\sqrt {13} }},\frac{{ 3}}{{\sqrt {13} }}} \right)\)
4
None of the above