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Let a → , b → and c → are three non-collinear vectors in a plane such that a → = 2 , b → = 5 and c → = 29 . If the angle between a → and c → is θ 1 and the angle between b → and c → is θ 2 , where θ 1 , θ 2 ∈ π 2 , π , then the value of θ 1 + θ 2 is equal to

Options

  1. A7 π 6
  2. B4 π 6
  3. C3 π 2
  4. D7 π 4

Correct answer

C. 3 π 2

Step-by-step solution

a → 2 + b → 2 = c → 2 (property of triangles) From the diagram, π - θ 1 + π - θ 2 = π 2 ⇒ θ 1 + θ 2 = 3 π 2

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