SOLUTION: How do you find all solutions for this quadratic type equation: x^4-5x^2-36=0

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Question 917149: How do you find all solutions for this quadratic type equation:
x^4-5x^2-36=0
Found 2 solutions by Alan3354, stanbon:
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
I would factor it, find 2 solutions for x^2, then get all 4 of them.
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x%5E4-5x%5E2-36+=+%28x%5E2+-+9%29%2A%28x%5E2+%2B+4%29+=+0

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
How do you find all solutions for this quadratic type equation:
x^4-5x^2-36=0
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Two numbers whose product is -36 and whose sum is -5
are -9 and +4
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Factor your problem to get:
(x^2 - 9)(x^2 + 4) = 0
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(x^2-9) = 0 or x^2+4 = 0
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x = +/- 3 or x = +/-2i
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Cheers,
Stan H.
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