document.write( "Question 1112034: The function
\n" ); document.write( "f(x)=4x^(3)−6x^(2)−672x−8
\n" ); document.write( "is decreasing on the interval (? , ?).
\n" ); document.write( "It is increasing on the interval ( −∞, ? ) and the interval ( ? , ∞ ).
\n" ); document.write( "The function has a local maximum at ?.
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Algebra.Com's Answer #727055 by Boreal(15235) $\"\"$ $\"About$

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f(x)=4x^(3)−6x^(2)−672x−8
\n" ); document.write( "f'(x)=12x^2-12x-672; f''(x)=24x-12
\n" ); document.write( "Set equal to 0 and factor out a 12
\n" ); document.write( "12(x^2-x-56)=0=12(x-8)(x+7)
\n" ); document.write( "x=8, -7, which are critical points.
\n" ); document.write( "when x=8, f''(x)=180, a minimum
\n" ); document.write( "when x=-7, f''(x)=-180, a maximum. The local maximum is at (-7, 3030)
\n" ); document.write( "it goes from -oo to -7, increasing, decreases on the interval (-7, 8) and increases on the interval (8, oo)\r
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