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Manipal MET2013MathematicsVector Algebra

If be the angle between the unit vectors a and b, then 2 is equal to

Options

  1. A1 2 |a-b|
  2. B1 2 |a+b|
  3. C|a-b| |a+b|
  4. D|a+b| |a-b|

Correct answer

B. 1 2 |a+b|

Step-by-step solution

aligned ( a + b ) ( a + b ) & = | a ^2 |+ | b ^2 |+2 a b & =1+1+2(1)(1) =2+2 a + b ^2 & =2 2 ^2 2 2 & = 1 2 | a + b | aligned

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