NCERT Example 27 - Vector Algebra
Question: Position vectors of A,B,C,D are i-hat+j-hat+k-hat, 2i-hat+5j-hat, 3i-hat+2j-hat-3k-hat, i-hat-6j-hat-k-hat. Find the angle between AB and CD; deduce they are collinear.
Answer: theta = pi; AB and CD are collinear.
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