SOLUTION: Use the rational zeros and synthetic division to factor f(x)=x^3+x^2-5x-2.

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Question 365546: Use the rational zeros and synthetic division to factor f(x)=x^3+x^2-5x-2.
Found 2 solutions by stanbon, ewatrrr:
Answer by stanbon(75887)   (Show Source): You can put this solution on YOUR website!
Use the rational zeros and synthetic division to factor f(x)=x^3+x^2-5x-2.
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Graphing I found a rational zero at x = 2
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Using synthetic division you can find the following:
2)....1....1....-5....-2
.......1....3.....1..|..0
Quotient: x^2+3x+1
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Use the Quadratic formula to find the other zeroes:
x = [-3 +- sqrt(9-4*1*1)]/2
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x = [-3 +- sqrt(5)]/2
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x = (-3+sqrt(5))/2 or x = (-3-sqrt(5))/2
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Cheers,
Stan H.

Answer by ewatrrr(24785)   (Show Source): You can put this solution on YOUR website!

Hi,
*Note: exploring the factors of -2, found that x = 2 works
x^2 + 3x + 1
__________________________
x - 2 | x^3 + x^2 - 5x - 2
- (x^3 -2x)
---------------
3x - 5x
- (3x - 6x)
---------
x - 2
- ( x - 2)
---------
0
x^2 + 3x + 1


x = 2 and

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