Teaching AWES Army Public School TGT Mock Test 2024 Mathematics Three Dimensional Geometry Direction ratios and Direction cosines
If a line has the direction ratios (3, 4, 5) then its direction cosines are
1
\(\left( {\frac{{ 3}}{{\sqrt {25} }},\frac{{4}}{{\sqrt {25} }},\frac{{ 5}}{{\sqrt {25} }}} \right)\)
2
\( \left( {\frac{{ 3}}{{5\sqrt {2} }},\frac{{4}}{{5\sqrt {2} }},\frac{{ 5}}{{5\sqrt {2} }}} \right)\)
3
\( \left( {\frac{{ 1}}{{\sqrt {20} }},\frac{{2}}{{\sqrt {20} }},\frac{{ 3}}{{\sqrt {20} }}} \right)\)
4
\(\left( {\frac{{ 3}}{{\sqrt {5} }},\frac{{4}}{{\sqrt {5} }},\frac{{ 5}}{{\sqrt {5} }}} \right)\)