Question 87621: I have tried this question for the past hour and I am so lost now that nothing is working. It states: find all zeros of the function X^3+3x^2-x+12
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! find all zeros of the function X^3+3x^2-x+12
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Graphing I find x=-4 is a zero
Using Synthetic Divisionyou can find two other zeroes, as follows:
-4).....1....3....-1....12
..........1....-1....3...|..0
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Remainder is zero
Quotient is x^2-x+3
Use the quadratic formula to find the zeroes of x^2-x+3
x = [1+-sqrt(1-4*1*3)]/2
x = [1+-isqrt(11)]/2
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So the zeroes are x=-4, x= [1+isqrt(11)]/2 and x= [1-isqrt(11)]/2
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Cheers,
Stan H.
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