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If 2-i 3 where i= -1 is a root of the equation x^2+a x+b=0 , then what is the value of (a+b) ?

Options

  1. A-11
  2. B-3
  3. C0
  4. D3

Correct answer

D. 3

Step-by-step solution

If 2- 3 i is one root. 2+ 3 i is other root -a C = Sum of roots - a =2- 3 i+2+ 3 i=4 a=-4 and b= product of roots b=(2- 3 i)(2+ 3 i)=4+3=7a+b=-4+7=3

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