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    I was doing practising pure maths papers and I came across this plane questions and I don't know how a part is done and the marking scheme shows a method I don't understand so can u guys please help me understand part D of this questions. thanks alot in advanceAttachment 723756
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    I can't comment on what's in the mark scheme as you haven't posted it, but the method I would suggest is:

    * Let x be the displacement from P to Q in the direction parallel to AB
    * Let y be the displacement from P to Q in the direction parallel to AD
    * Let z be the height difference between P and Q

    The directions of x, y and z are mutually at right angles.

    Then PQ = SQRT(x^2 + y^2 + z^2)

    This is Pythagoras in three dimensions.
 
 
 
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Updated: February 9, 2018
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