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MHT CET2017MathematicsVector Algebra

Let P Q R S be a quadrilateral. If M and N are midpoints of the sides P Q and R S respectively then P S → + Q R → =

Options

  1. A3   M N →
  2. B4   M N →
  3. C2   M N →
  4. D5 M N →

Correct answer

C. 2   M N →

Step-by-step solution

m ¯ = p ¯ + q ¯ 2 n ¯ = r ¯ + s ¯ 2 P S ¯ + Q R ¯ = ( S ¯ − p ¯ ) + ( r ¯ − q ¯ ) = r ¯ + s ¯ - ( p ¯ + q ¯ ) = 2 n ¯ - 2 m ¯ = 2 ( n ¯ - m ¯ ) = 2 M N ¯

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