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JEE Main202522 Jan 2025Evening ShiftMathematicsVector AlgebraActual

Let a and b be two unit vectors such that the angle between them is 3 . If a +2 b and 3 a - b are perpendicular to each other, then the number of values of in [-1,3] is :

Options

  1. A2
  2. B1
  3. C0
  4. D3

Correct answer

C. 0

Step-by-step solution

aligned & a b = 1 2 & Now ( a +2 b ) (3 a - b )=0 & 3 a a - ^2 a b +6 a b -2 b b =0 & 3 - ^2 2 +3-2 =0 & ^2-2 -6=0 & =1 7 & number of values =0 aligned

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