Question
Question: If co-ordinates of points A, B, C and D are (1, 2, 3) ; (4, 5, 7) ; (–4, 3, –6) and (2, 9, 2) respe...
If co-ordinates of points A, B, C and D are
(1, 2, 3) ; (4, 5, 7) ; (–4, 3, –6) and (2, 9, 2) respectively ; then the angle between AB and CD is
A
p/6
B
p/4
C
p/3
D
None
Answer
None
Explanation
Solution
D.R's of AB = 3, 3, 4
D.R's of CD = 6, 6, 8
as 
\ AB || CD
\ required angle is zero.