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If the position vectors of points A and B are  and  respectively, then what is the length of ?

  1. √5
  2. 3√5
  3. 2√5 
  4. 4

Answer (Detailed Solution Below)

Option 3 : 2√5 
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Detailed Solution

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Concept:

If A and B are points with position vectors  respectively then 

If  is a vector then the magnitude of the vector is given by

 

Calculation:

Given: The position vectors of points A and B are  and  respectively

As we know, If A and B are points with position vectors  respectively then 

As we know that, If  is a vector then the magnitude of the vector is given by

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