document.write( "Question 927600: Find the equation for a hyperbola with eccentricity 3/2 and directrix x=2 \n" ); document.write( "
Algebra.Com's Answer #563156 by Edwin McCravy(20062)\"\" \"About 
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document.write( "The easiest hyperbola with directrix x=2 and eccentricity 3/2\r\n" );
document.write( "is found by taking the focus to be the origin.\r\n" );
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document.write( "We take an arbitrary point (x,y) on the hyperbola, and, (in blue)\r\n" );
document.write( "draw one line from the arbitrary point (x,y) to the focus (0,0) and\r\n" );
document.write( "another line directly to and perpendicular to the directrix x=2\r\n" );
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document.write( "The ratio of the two blue lines is equal to the eccentricity 3/2.\r\n" );
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document.write( "The horizontal blue line has length |2-x|,\r\n" );
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document.write( "The slanted blue line has length \"sqrt%28%28x-0%29%5E2%2B%28y-0%29%5E2%29\" or\r\n" );
document.write( "\"sqrt%28x%5E2%2By%5E2%29\"\r\n" );
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document.write( "So we set their ratio equal to 3/2\r\n" );
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document.write( " \"sqrt%28x%5E2%2By%5E2%29%2Fabs%282-x%29\"\"%22%22=%22%22\"\"3%2F2\"\r\n" );
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document.write( "Square both sides\r\n" );
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document.write( "\"%28x%5E2%2By%5E2%29%2F%282-x%29%5E2\"\"%22%22=%22%22\"\"9%2F4\"\r\n" );
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document.write( "\"4%28x%5E2%2By%5E2%29\"\"%22%22=%22%22\"\"9%282-x%29%5E2\"\r\n" );
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document.write( "\"4x%5E2%2B4y%5E2\"\"%22%22=%22%22\"\"9%284-4x%2Bx%5E2%29\"\r\n" );
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document.write( "\"4x%5E2%2B4y%5E2\"\"%22%22=%22%22\"\"36-36x%2B9x%5E2%29\"\r\n" );
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document.write( "\"-5x%5E2%2B36x%2B4y%5E2-36=0\"\r\n" );
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document.write( "\"5x%5E2-36x-4y%5E2%2B36=0\"\r\n" );
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document.write( "Edwin

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