SOLUTION: I need help factoring this: x^4-6x^2+7

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Question 494615: I need help factoring this: x^4-6x^2+7
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
x^4-6x^2+7
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Let x^2 = w
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w^2 - 6w + 7
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Use the quadratic formula to get:
w = [6 +- sqrt(36 - 4*7]/2
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w = [6 +-sqrt(8)]/2
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w = [3 +- sqrt(2)]
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solve for "x":
x^2 = 3+sqrt(2) or x^2 = 3-sqrt(2)
x = sqrt[3+sqrt(2)] or x = sqrt[3-sqrt(2)]
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Cheers,
Stan H.