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Let a unit vector k ˆ z j ˆ y i ˆ x u ˆ + + = make angles 3 , 2 π π and 3 2 π with the vectors k ˆ 2 1 i ˆ 2 1 + , k ˆ 2 1 j ˆ 2 1 + and j ˆ 2 1 i ˆ 2 1 + respectively, if i ˆ 2 1 v = r + j ˆ 2 1 + k ˆ 2 1 , then 2 | v – u ˆ | r is equal to

1. 9
2. 7
3. 2 11
4. 2 5

Correct answer: 2 5

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