SOLUTION: Given f(x)=(5/3)x^3+x^2-3x+1, for what value(s) for x does f(x) have a horizontal Tangent line?

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Question 1026705: Given f(x)=(5/3)x^3+x^2-3x+1, for what value(s) for x does f(x) have a horizontal Tangent line?
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Given f(x)=(5/3)x^3+x^2-3x+1, for what value(s) for x does f(x) have a horizontal Tangent line?
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That would be where the slope is zero.
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f'(x) = 5x^2 + 2x -3
Solve:: 5x^2 + 2x-3 = 0
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5x^2 + 5x-3x - 3 = 0
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5x(x+1)-3(x+1) = 0
(x+1)(5x-3) = 0
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Ans: where x = -1 and where x = 3/5
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Cheers,
Stan H.
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