document.write( "Question 1099085: How do you convert y= -(x^2/36)+1 to standard form \n" ); document.write( "
Algebra.Com's Answer #713494 by Edwin McCravy(20055)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "\"y=+-%28x%5E2%2F36%5E%22%22%29%2B1\"\r\n" );
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document.write( "Multiply both sides by 36\r\n" );
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document.write( "\"36y=-x%5E2%2B36\"\r\n" );
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document.write( "Add x2 to both sides\r\n" );
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document.write( "\"x%5E2%2B36y=36\"\r\n" );
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document.write( "Add -36y to both sides:\r\n" );
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document.write( "\"x%5E2=-36y%2B36\"\r\n" );
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document.write( "Factor out -36 on the right side:\r\n" );
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document.write( "\"x%5E2=-36%28y-1%29\"\r\n" );
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document.write( "Write x as (x-0)\r\n" );
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document.write( "\"%28x-0%29%5E2=-36%28y-1%29\"\r\n" );
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document.write( "Compares to standard form with\r\n" );
document.write( "vertical axis of symmetry x = 0,\r\n" );
document.write( "which is the y-axis\r\n" );
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document.write( "\"%28x-h%29%5E2=4p%28y-k%29\"\r\n" );
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document.write( "vertex = (h,k) = (0,1)\r\n" );
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document.write( "4p = -36\r\n" );
document.write( " p = -9\r\n" );
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document.write( "p is negative, so parabola opens downward\r\n" );
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document.write( "Focus is |p| = |-9| = 9 units below vertex,\r\n" );
document.write( "so focus is (0,-8)\r\n" );
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document.write( "Directrix is the (green) line 9 units above the vertex,\r\n" );
document.write( "which is the horizontal line whose equation is\r\n" );
document.write( "y = 10\r\n" );
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document.write( "Edwin
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