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Let → a = k ˆ 2 – j ˆ i ˆ 2 + and → b = j ˆ i ˆ + . Let → c be a vector such that | → c – → a | = 3, |( → a × → b ) × → c | = 3 and the angle between → c and → a × → b be 30º. Then → a · → c is equal to :

1. 2
2. 5
3. 8 1
4. 8 25 Students may find similar question in CP exercise sheet : [ JEE Main, Chapter : Vector, Page 55, Ex. 5A, Q. No. 10 ] [ JEE Advance, Chapter : Vector, Page 38, Ex. 4, Q. No. 35 ]

Correct answer: 2

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