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Question 482262: find domain and range of 1/(root of x3-4x)
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! find domain and range of 1/(root of x^3-4x)
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x^3-4x >= 0
x(x^2-4) >= 0
x(x-2)(x+2) >= 0
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Draw a number line.
Plot x = -2; x = 0; x = 2
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Test 4 value intervals on the line:
x(x-2)(x+2) >= 0
x = -10, you get -*-*- > 0 ; false
x = -1, you get -*-*+ >0 ; true
x = +1, you get -*+*+ >0 0 ; false
x = 10, you get +*+*+ > 0 ; true
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Domain: All Real Numbers [-2,0] U {2.+oo)
Range: All Real Numbers >= 0
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Cheers,
Stan H.
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