SOLUTION: n=3; 4 and 2i are real zeros f(1)=15 Answer: f (x)= ?

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Question 1056141: n=3;
4 and 2i are real zeros
f(1)=15
Answer: f (x)= ?
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
n=3;
4 and 2i are real zeros
f(1)=15
------
If 2i is a zero then -2i is also.
--> a*(x-4)*(x-2i)*(x+2i)
= a*(x-4)*(x^2+4)
= a*(x^3 - 4x^2 + 4x - 16)
f(1) = a*(1 - 4 + 4 - 16) = 15
--> a = -1
f(x) = -x^3 + 4x^2 - 4x + 16