COMEDK2025MathematicsVector AlgebraActual

If a and b are two vectors such that a b =| a b | then the angle between a and b is

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Correct answer

A. 4

Step-by-step solution

Given the condition a b = | a b | . Using the definitions of dot product and cross product, we have | a | | b | = | a | | b | , where is the angle between the vectors a and b . Assuming a 0 and b 0 , we can divide both sides by | a | | b | . This yields = . Dividing by (assuming 0 ), we get = 1 . Since is the angle between two vectors, 0 . The value of satisfying = 1 in this range is = 4 . Answer: 4

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