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If 3 + 2i is a solution for x^2 + bx + c = 0, where b and c are real numbers, then what are b and c?

 Feb 20, 2021
 #1
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If  3  + 2i  is  a root  then  so is  3  -2i

 

-b  =  the sum of the  roots =  6

So  b  =  - 6

 

And  c  = the product of the  roots  =  (3 + 2i) ( 3 - 2i)  =  9 - 4i^2  =   9 - 4 (-1)  =  13

 

So the polynoimial is

 

x^2 - 6x  + 13

 

cool cool cool

 Feb 20, 2021

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