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MHT CET202122 Sep 2021Morning ShiftMathematicsVector AlgebraActual

If a + b + c = 0 with | a |=3,| b |=5 and | c |=7 , then angle between a and b is

Options

  1. A( 3 )^c
  2. B( 4 3 )^c
  3. C( 2 3 )^c
  4. D^ c

Correct answer

A. ( 3 )^c

Step-by-step solution

aligned & a + b =- c | a + b |^2=| c |^2 & | a |^2+| b |^2+2| a || b | =| c |^2 & (3)^2+(5)^2+2(3)(5) =(7)^2 & = 49-34 30 = 1 2 = 3 aligned

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