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If a , b and c are unit vectors satisfying a - 3 b + c = 0 , then the angle between the vectors a and c is :

Options

  1. A4
  2. B3
  3. C6
  4. D2

Correct answer

B. 3

Step-by-step solution

Let angle between a and c be . Now, a - 3 b + c = 0 aligned & ( a + c )= 3 b & ( a + c ) ( a + c )=3( b b ) & a a + a c + c a + c c =3 1 & 1+2 +1=3 & = 1 2 = 3 aligned

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