document.write( "Question 81199: Graph y=3x^2-5x-9. Also find the vertex \n" ); document.write( "

Algebra.Com's Answer #58203 by Edwin McCravy(20060) $\"\"$ $\"About$

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document.write( "Graph y =  -  - 9. Also find the vertex\r\n" );
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document.write( "a = 3, b = -5, c = -9\r\n" );
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document.write( "Let's find the vertex (h,k) first, where\r\n" );
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document.write( "h =  and k =  +  + \r\n" );
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document.write( "and then the y-intercept (0,c)\r\n" );
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document.write( "h =  = \r\n" );
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document.write( "k =  +  +  \r\n" );
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document.write( "k =  +  - \r\n" );
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document.write( "k =  -  - \r\n" );
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document.write( "k =  -  - \r\n" );
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document.write( "k =  \r\n" );
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document.write( "So the vertex is (h,k) = (, )\r\n" );
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document.write( "or for plotting purposes approximately (.8, -11.1)\r\n" );
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document.write( "the y-intercept (0,c) = (0,-9)\r\n" );
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document.write( "So plot the vertex and the y-intercept\r\n" );
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document.write( "Draw the left half of the parabola through the\r\n" );
document.write( "y-intercept and bottoming out at the vertex:\r\n" );
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document.write( "Then draw the right half to match the left half:\r\n" );
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document.write( "Edwin

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