SOLUTION: Form a third degree polynomial function with real coefficients such that 2+i and -1 are zeroes

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Question 850065: Form a third degree polynomial function with real coefficients such that 2+i and -1 are zeroes
Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
That includes zero at 2-i.

p=%28x%2B1%29%28x-%282%2Bi%29%29%28x-%282-i%29%29
p=%28x%2B1%29%28%28x-2%29-i%29%28%28x-2%29%2Bi%29
p=%28x%2B1%29%28%28x-2%29%5E2%2B1%29--------Do you understand that step?
p=%28x%2B1%29%28x%5E2-4x%2B4%2B1%29
highlight%28p=%28x%2B1%29%28x%5E2-4x%2B5%29%29
%28x%2B1%29x%5E2-4x%28x%2B1%29%2B5x%2B5
x%5E3%2Bx%5E2-4x%5E2-4x%2B5x%2B5
highlight%28p=x%5E3-2x%5E2%2Bx%2B5%29