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Topic: Another Radical (Read 341 times) |
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ThudnBlunder
wu::riddles Moderator Uberpuzzler
The dewdrop slides into the shining Sea
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Posts: 4489
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Another Radical
« on: Apr 18th, 2007, 8:09am » |
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Let a = 10/33 Evaluate 3(2 + a) + 3(2 - a)
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« Last Edit: Apr 18th, 2007, 8:23am by ThudnBlunder » |
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THE MEEK SHALL INHERIT THE EARTH.....................................................................er, if that's all right with the rest of you.
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SMQ
wu::riddles Moderator Uberpuzzler
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Re: Another Radical
« Reply #1 on: Apr 18th, 2007, 8:31am » |
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Following Eigenray's methodology from this thread: x = (u + v)3 --> x3 = u3 + v3 + 3xuv = 4 + 3x3(4 - b2) = 4 + 3x3(8/27) = 4 + 2x --> x3 - 2x - 4 = 0 --> (x - 2)(x2 + 2x + 2) = 0 Which has a unique positive real root of x = 2! --SMQ
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--SMQ
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