document.write( "Question 1132430: A point P(x,y) moves so that its distance from the point K(2,5) is twice its distance from the line x=-1. Find the equation of the locus of P. \n" ); document.write( "
Algebra.Com's Answer #749498 by MathLover1(20849)\"\" \"About 
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The distance from \"P\"(\"x\",\"y\") to the line \"x=-1\" will taken from
\n" ); document.write( "the perpendicular distance as shortest which will be a horizontal distance since \"x=-1\" is a vertical line.\r
\n" ); document.write( "\n" ); document.write( "This distance will be the difference in the \"x\" coordinates
\n" ); document.write( "stated as a positive or \"abs%28x-%28-1%29%29\" => \"abs%28x%2B1%29\"
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\n" ); document.write( "Since we want the distance from \"P\"(\"x\",\"y\") to \"K\"(\"2\",\"5\") to be
\n" ); document.write( "twice the distance from (\"x\",\"y\") to \"x=-1\" we have:
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\n" ); document.write( "\"sqrt%28%28x-2%29%5E2%2B%28y-5%29%5E2%29+=+2%2Aabs%28x%2B1%29\" ... square both sides\r
\n" ); document.write( "\n" ); document.write( "Note that since squaring \"abs%28x%2B1%29\" will automatically result in a positive we will no longer need the absolute value sign.
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\n" ); document.write( "\"%28x-2%29%5E2%2B%28y-5%29%5E2+=+4%28x%2B1%29%5E2\"
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\n" ); document.write( "\"x%5E2-4x%2B4%2By%5E2-10y%2B25+=+4%28x%5E2%2B2x%2B1%29\"\r
\n" ); document.write( "\n" ); document.write( "\"x%5E2-4x+%2By%5E2-10y%2B29+=+4x%5E2%2B8x%2B4\"
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\n" ); document.write( "\"0+=+4x%5E2%2B8x%2B4-%28x%5E2-4x+%2By%5E2-10y%2B29%29\"
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\n" ); document.write( "\"+4x%5E2%2B8x%2B4-x%5E2%2B4x+-y%5E2%2B10y-29=0\"\r
\n" ); document.write( "\n" ); document.write( "\"3x%5E2+%2B+12x+-+y%5E2+%2B+10y+=+25\"
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\n" ); document.write( "Note this is becoming the equation of a hyperbola.\r
\n" ); document.write( "\n" ); document.write( "We want standard form \"%28x-h%29%5E2%2Fa%5E2+-+%28y-k%29%5E2%2Fb%5E2+=+1+\":\r
\n" ); document.write( "\n" ); document.write( "We need to do some complete the square work here.
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\n" ); document.write( "\"3%28x%5E2%2B4x%29+-+%28y%5E2-10y%29+=+25\"\r
\n" ); document.write( "\n" ); document.write( "\"3%28x%5E2%2B4x%2B4%29+-+%28y%5E2-10y+%2B+25%29+=+25+%2B+12+-+25\"
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\n" ); document.write( "\"3%28x%2B2%29%5E2+-+%28y-5%29%5E2+=+12\"
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\n" ); document.write( "\"%28x%2B2%29%5E2%2F4+-+%28y-5%29%5E2%2F12+=+1\"
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\n" ); document.write( "We have a hyperbola centered at (\"h\",\"k\") or (\"-2\",\"5\").=>the equation of the locus of \"P\"\r
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