SOLUTION: Can you help me find a third degree polynomial with a polynomial function with real coefficients that has -3 and i as zeros and such that f(1) =8?

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Question 1095516: Can you help me find a third degree polynomial with a polynomial function with real coefficients that has -3 and i as zeros and such that f(1) =8?
Found 2 solutions by Alan3354, greenestamps:
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
Can you help me find a third degree polynomial with a polynomial function with real coefficients that has -3 and i as zeros and such that f(1) =8?
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You do Step 1:
f(x) = (x+3)*(x-i)*(x+i)

Answer by greenestamps(13200) About Me  (Show Source):
You can put this solution on YOUR website!

If the polynomial has real coefficients, then complex or imaginary roots must occur in conjugate pairs. So if i is a root, -i is another root.

That makes the three roots -3, i, and -1; the polynomial is of the form
f%28x%29+=+a%28x%2B3%29%28x-i%29%28x%2Bi%29
where a is a constant.

The value of the constant a is determined using the given information that f(1) is 8. So to find the value of a and thus finish finding the exact polynomial, solve the equation f(1) = 8:
a%281%2B3%29%281-i%29%281%2Bi%29+=+8

I'll let you finish from there....