document.write( "Question 1207163: two circles intersect (a nd b) and share a common chord (cd). the radius of circle a is 10in, radius circle b = 16 in. distance between centers, 22 in. find cd. \n" ); document.write( "
Algebra.Com's Answer #844876 by MathLover1(20850)\"\" \"About 
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circle \"a\":
\n" ); document.write( "\"r=10in\"\r
\n" ); document.write( "\n" ); document.write( "circle \"b\":
\n" ); document.write( "\"r=16in\"\r
\n" ); document.write( "\n" ); document.write( "distance between centers=\"22in\"\r
\n" ); document.write( "\n" ); document.write( "if we place the center of the circle a on \"x\"-ais, at point (\"-11\",\"0\"), than the center of the circle b will be at (\"11\",\"0\") and the distance between them is \"22in\"\r
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\n" ); document.write( "\n" ); document.write( "now we have equations:\r
\n" ); document.write( "\n" ); document.write( "circle \"a\"\r
\n" ); document.write( "\n" ); document.write( "\"%28x-%28-11%29%29%5E2%2B%28y-0%29%5E2=10%5E2+\"\r
\n" ); document.write( "\n" ); document.write( "\"%28x%2B11%29%5E2%2By%5E2=100\"\r
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\n" ); document.write( "\n" ); document.write( "circle\"+b\"\r
\n" ); document.write( "\n" ); document.write( "\"%28x-11%29%5E2%2B%28y-0%29%5E2=16%5E2+\"\r
\n" ); document.write( "\n" ); document.write( "\"%28x-11%29%5E2%2By%5E2=256\"\r
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\n" ); document.write( "\n" ); document.write( "find intersection points by solving this system:\r
\n" ); document.write( "\n" ); document.write( "\"%28x-11%29%5E2%2By%5E2=256\"
\n" ); document.write( "\"%28x%2B11%29%5E2%2By%5E2=100\"
\n" ); document.write( "-----------------------------subtract\r
\n" ); document.write( "\n" ); document.write( "\"%28x-11%29%5E2%2By%5E2-%28x%2B11%29%5E2-y%5E2=256-100\"\r
\n" ); document.write( "\n" ); document.write( "\"%28x-11%29%5E2-%28x%2B11%29%5E2=156\"\r
\n" ); document.write( "\n" ); document.write( "\"x%5E2+-+22x+%2B+121-%28x%5E2+%2B+22x+%2B+121%29=156\"\r
\n" ); document.write( "\n" ); document.write( "\"x%5E2+-+22x+%2B+121-x%5E2+-22x+-+121=156\"\r
\n" ); document.write( "\n" ); document.write( " \"-+22x++-22x+=156\"\r
\n" ); document.write( "\n" ); document.write( "\"-+44x+=156\"\r
\n" ); document.write( "\n" ); document.write( "\"x=156%2F-44\"\r
\n" ); document.write( "\n" ); document.write( "\"x=-39%2F11\"\r
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\n" ); document.write( "\n" ); document.write( "plug it in\r
\n" ); document.write( "\n" ); document.write( "\"%28-39%2F11%2B11%29%5E2%2By%5E2=100\"\r
\n" ); document.write( "\n" ); document.write( "\"6724%2F121%2By%5E2=100\"\r
\n" ); document.write( "\n" ); document.write( "\"y%5E2=100-6724%2F121\"\r
\n" ); document.write( "\n" ); document.write( "\"y%5E2=5376%2F121\"\r
\n" ); document.write( "\n" ); document.write( "\"y=sqrt%285376%2F121%29\"\r
\n" ); document.write( "\n" ); document.write( "\"y+=+%2816+sqrt%2821%29%29%2F11+\"or \"y+=-+%2816+sqrt%2821%29%29%2F11\"\r
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\n" ); document.write( "\n" ); document.write( "solutions:\r
\n" ); document.write( "\n" ); document.write( "\"x+=+-39%2F11\", \"y+=+%2816sqrt%2821%29%29%2F11\"\r
\n" ); document.write( "\n" ); document.write( "or\r
\n" ); document.write( "\n" ); document.write( "\"x+=+-39%2F11\", \"y+=+-%2816sqrt%2821%29%29%2F11\"\r
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\n" ); document.write( "\n" ); document.write( "intersection points are\r
\n" ); document.write( "\n" ); document.write( "(\"-39%2F11\", \"%2816sqrt%2821%29%29%2F11\") and (\"-39%2F11\", \"-%2816sqrt%2821%29%29%2F11\") \r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "distance between is: two times \"y\" value \r
\n" ); document.write( "\n" ); document.write( "\"d=2%2A%2816sqrt%2821%29%29%2F11=13.33\"\r
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\n" ); document.write( "\n" ); document.write( "The length of \"cd\" is \"13.33in\".\r
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