document.write( "Question 636499: f(x)=x2 + 2x - 9\r
\n" ); document.write( "\n" ); document.write( "determine whether the given quadratic function has a minmum or maximun value. then find the coordinated of the mininmun or maximun point.
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Algebra.Com's Answer #401058 by josmiceli(19441)\"\" \"About 
You can put this solution on YOUR website!
\"+f%28x%29+=+x%5E2+%2B+2x+-+9+\"
\n" ); document.write( "Since the coefficient of the squared term is positive
\n" ); document.write( "( +1 ), then the function has a minimum.
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\n" ); document.write( "The \"+x+\" value of the minimum will
\n" ); document.write( "be at \"+-b+%2F+%282a%29+\" when the
\n" ); document.write( "equation is in the form \"+f%28x%29+=+a%2Ax%5E2+%2B+b%2Ax+%2B+c+\"
\n" ); document.write( "\"+-b%2F%282a%29+=+-2+%2F+%282%2A1%29+\"
\n" ); document.write( "\"+-2+%2F+%282%2A1%29+=+-1+\"
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\n" ); document.write( "Plug this back into the equation
\n" ); document.write( "\"+f%281%29+=+%28-1%29%5E2+%2B+2%2A%28-1%29+-+9+\"
\n" ); document.write( "\"+f%281%29+=+1+-+2+-+9+\"
\n" ); document.write( "\"+f%281%29+=+-10+\"
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\n" ); document.write( "So the minimum is at (-1,-10)
\n" ); document.write( "Here's a plot:
\n" ); document.write( "\"+graph%28+400%2C+400%2C+-10%2C+10%2C+-20%2C+10%2C+x%5E2+%2B+2x+-+9%29+\"
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