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Most Important Selected Qs for JEE AdvancedMathematicsVector Algebra

If P , Q , R are three points such that | PQ |=3 &| QR |=4 , then the value of PR ( QR + QP ) is

Correct answer

7

Step-by-step solution

|( q - p )|=3 q ^2+ p ^2-2 p q =9...(1)| r - q |=4 q ^2+ r ^2-2 r q =16...(2)(2) -(1) ( r ^2- p ^2 )-2 q ( r - p )=7 PR ( QR + QP )=7

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