Question
Mathematics Question on Three Dimensional Geometry
The projections of a vector on the three coordinate axis are 6,−3,2 respectively. The direction cosines of the vector are
A
6,−3,2
B
56,−53,52
C
76,−73,72
D
−76,−73,72
Answer
76,−73,72
Explanation
Solution
Projection of a vector on coordinate axis are x2−x1,y2−y1,z2−z1 x2−x1=6,y2−y1=−3,z2−z1=2 (x2−x1)2+(y2−y1)2+(z2−z1)2=36+9+4=7 The D.C?? of the vector are 76,−73,72