document.write( "Question 1137032: find the equation describing all points equidistant from the x-axis and the point (0,2)
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Algebra.Com's Answer #754872 by ikleyn(52797)\"\" \"About 
You can put this solution on YOUR website!
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\n" ); document.write( "\n" ); document.write( "            The solution by @MathLover1 is incorrect.\r
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\n" ); document.write( "\n" ); document.write( "            It is incorrect,  because the formula for the distance from the point (0,2) to the point  (x,y) is   \"sqrt%28x%5E2+%2B+%28y-2%29%5E2%29\",  and not   \"sqrt%28x%5E2+-+%28y-2%29%5E2%29\".\r
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\n" ); document.write( "\n" ); document.write( "            The final curve should be a parabola,  not a hyperbola.\r
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\n" ); document.write( "\n" ); document.write( "            I know it very well,  since I solved similar problems several times at this forum.\r
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\n" ); document.write( "\n" ); document.write( "            The correct solution is below.\r
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document.write( "The distance from  (\"x\", \"y\") to the x-axis is  |y|.\r\n" );
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document.write( "The distance from   (\"x\", \"y\") to the point (\"0\", \"2\") is  \"sqrt%28x%5E2+%2B+%28y+-+2%29%5E2%29\".\r\n" );
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document.write( "The base equation is\r\n" );
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document.write( "|y| = \"sqrt%28x%5E2+%2B+%28y+-+2%29%5E2%29\".\r\n" );
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document.write( "Square both sides of this equation and solve for\"+y\".  \r\n" );
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document.write( "\"y%5E2\" = \"x%5E2+%2B+%28y+-+2%29%5E2\"\r\n" );
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document.write( "\"y%5E2\" = \"x%5E2+%2B+%28y%5E2+-+4y%2B4%29\"\r\n" );
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document.write( "\"0\" = \"x%5E2+-+4y+%2B+4\"\r\n" );
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document.write( "4y =  \"x%5E2+%2B+4\"\r\n" );
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document.write( "y = \"%281%2F4%29%2Ax%5E2+%2B+1\"    <==========>  parabola with the branches upward; the vertex at the point (0,1)\r\n" );
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document.write( "    \"graph+%28+400%2C+400%2C+-10%2C+10%2C+-5%2C+10%2C%0D%0A+++++++++++++x%5E2%2F4+%2B+1%0D%0A%29\"\r\n" );
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document.write( "                Plot  y = \"x%5E2%2F4\" + 1\r\n" );
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