document.write( "Question 1111276: Find the minimum slope of the line tangent to the curve y = x³-3x²+6x+3. \n" ); document.write( "
Algebra.Com's Answer #726336 by KMST(5328)\"\" \"About 
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The slope of the line tangent to the curve \"y+=+x%5E3-3x%5E2%2B6x%2B3\"
\n" ); document.write( "for each value of \"x\" is the value of the derivative,
\n" ); document.write( "\"dy%2Fdx=3x%5E2-6x%2B5\" .
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\n" ); document.write( "\n" ); document.write( "\"slope=3x%5E2-6x%2B5\" is a quadratic polynomial and graphs as a parabola.
\n" ); document.write( "You are asked for the minimum value of that expression,
\n" ); document.write( "and there are several ways to get to the result.
\n" ); document.write( "Can you figure out what way your teacher would favor?
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\n" ); document.write( "Maybe your teacher expects you to find the minimum of
\n" ); document.write( "\"slope=3x%5E2-6x%2B5\" by looking at
\n" ); document.write( "zeros and changes of sign of \"d%28slope%29%2Fdx=6x-6\" .
\n" ); document.write( "As \"d%28slope%29%2Fdx%3C0\" for \"x%3C1\" ,
\n" ); document.write( "\"d%28slope%29%2Fdx=0\" for \"x=1\" , and
\n" ); document.write( "\"d%28slope%29%2Fdx%3E0\" for \"x%3E1\" ,
\n" ); document.write( "there is a minimum at \"x=1\" .
\n" ); document.write( "The minimum slope, for \"x=1\" is
\n" ); document.write( "\"slope=3%2A1%5E2-6%2A1%2B5=3-6%2B5=2\" .
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\n" ); document.write( "Alternately, if you memorized class information,
\n" ); document.write( "you know that the expression \"ax%5E2%2Bbx%2Bc\" with \"a%3E0\"
\n" ); document.write( "has a minimum at \"x=%28-b%29%2F%222+a%22\" .
\n" ); document.write( "Maybe your teacher expects you to do that,
\n" ); document.write( "find that the minimum is at \"x=%28-%28-6%29%29%2F%282%2A3%29=6%2F6=1\" ,
\n" ); document.write( "and calculate that for \"x=1\" ,
\n" ); document.write( "\"slope=3%2A1%5E2-6%2A1%2B5=3-6%2B5=2\" .
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\n" ); document.write( "You could just use your algebra knowledge (no memorization)
\n" ); document.write( "and \"complete the square\" like this
\n" ); document.write( "\"slope=3x%5E2-6x%2B5\"
\n" ); document.write( "\"slope%2F3=x%5E2-2x%2B5%2F3\"
\n" ); document.write( "\"slope%2F3=%28x-1%29%5E2%2B5%2F3-1\"
\n" ); document.write( "\"slope%2F3=%28x-1%29%5E2%2B2%2F3\"
\n" ); document.write( "\"slope=3%28%28x-1%29%5E2%2B2%2F3%29\"
\n" ); document.write( "\"slope=3%28x-1%29%5E2%2B2%29\"
\n" ); document.write( "As \"%28x-1%29%5E2%3E=0\" , \"slope%3E=3\"
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