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KCET2015MathematicsDeterminants

If ( ) and ( ) are the roots of ( x²-a x+b²=0 ), then ( ²+ ² ) is equal to

Options

  1. A( a²-2 b² )
  2. B( 2 a²-b² )
  3. C( a²-b² )
  4. D( a²+b² )

Correct answer

A. ( a²-2 b² )

Step-by-step solution

Given equation, x²-a x+b²=0 (1) We know that, sum of the roots is given by + =a and the product of the roots is given by =b² Now, ²+ ²=( + )²-2 =a²-2 b²

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