document.write( "Question 1208001: if f (x) = 1/(1 - x) , then (f(f(f(f...f)(sqrt2),(45 times) = ...., A) 0, B)(2 - sqrt2)/2, C)(2 + sqrt2)/2, D) 1, E) sqrt2 \n" ); document.write( "
Algebra.Com's Answer #846108 by ikleyn(52884)\"\" \"About 
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\n" ); document.write( "If f (x) = 1/(1 - x) , then (f(f(f(f...f)(sqrt2),(45 times) = ...., \r
\n" ); document.write( "\n" ); document.write( "A) 0, \r
\n" ); document.write( "\n" ); document.write( "B) (2 - sqrt2)/2, \r
\n" ); document.write( "\n" ); document.write( "C) (2 + sqrt2)/2, \r
\n" ); document.write( "\n" ); document.write( "D) 1, \r
\n" ); document.write( "\n" ); document.write( "E) sqrt2.
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document.write( "If f(x) = \"1%2F%281-x%29\",  \r\n" );
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document.write( "then  f(f(x)) = \"1%2F%281-1%2F%281-x%29%29\" = \"%281-x%29%2F%28%281-x%29-1%29\" = \"%28x-1%29%2Fx\",\r\n" );
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document.write( "then  f(f(f(x))) = \"1%2F%281-%28x-1%29%2Fx%29\" = \"x%2F%28x-x%2B1%29\" = x.\r\n" );
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document.write( "Thus, applying function f to any real number x =/= 1,  x =/= 0  three times, we get x again.\r\n" );
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document.write( "In other words,  f(f(f(x))) == x identically, for all real x =/= 1,  x =/= 0.\r\n" );
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document.write( "So, for example,  \"f%28f%28f%28sqrt%282%29%29%29%29\" = \"sqrt%282%29\";  \"f%28f%28f%28sqrt%283%29%29%29%29\" = \"sqrt%283%29\";  \"f%28f%28f%28sqrt%285%29%29%29%29\" = \"sqrt%285%29\";  \"f%28f%28f%28sqrt%287%29%29%29%29\" = \"sqrt%287%29\";  \r\n" );
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document.write( "                  \"f%28f%28f%28root%283%2C2%29%29%29%29\" = \"root%283%2C2%29\";  \"f%28f%28f%28root%283%2C3%29%29%29%29\" = \"root%283%2C3%29\";  \"f%28f%28f%28root%283%2C5%29%29%29%29\" = \"root%283%2C5%29\";  \"f%28f%28f%28root%283%2C7%29%29%29%29\" = \"root%283%2C7%29\",  and so on.\r\n" );
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document.write( "Since 45 is a multiple of 3,  f applied to  \"sqrt%282%29\"  45 times is  \"sqrt%282%29\";\r\n" );
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document.write( "                              f applied to  \"sqrt%283%29\"  45 times is  \"sqrt%283%29\";\r\n" );
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document.write( "                              f applied to  \"sqrt%285%29\"  45 times is  \"sqrt%285%29\";\r\n" );
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document.write( "                              f applied to  \"sqrt%287%29\"  45 times is  \"sqrt%287%29\";\r\n" );
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document.write( "                              f applied to  \"root%283%2C2%29\"  45 times is  \"root%283%2C2%29%29\";\r\n" );
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document.write( "                              f applied to  \"root%283%2C3%29\"  45 times is  \"root%283%2C3%29%29\";\r\n" );
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document.write( "                              f applied to  \"root%283%2C5%29\"  45 times is  \"root%283%2C5%29%29\";\r\n" );
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document.write( "                              f applied to  \"root%283%2C7%29\"  45 times is  \"root%283%2C7%29%29\",\r\n" );
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document.write( "and so on.\r\n" );
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\n" ); document.write( "\n" ); document.write( "Solved and significantly expanded.\r
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\n" ); document.write( "\n" ); document.write( "For example,  f applied  2025  times to the number  \"root%282025%2C2025%29%29\"  is  \"root%282025%2C2025%29\".\r
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\n" ); document.write( "\n" ); document.write( "Similarly,  f  applied  2025  times to the number  \"2025%5E2025\"  is  \"2025%5E2025\".\r
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\n" ); document.write( "\n" ); document.write( "As well as  f  applied  2025  times to the number  2025!  is  2025! , again.\r
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\n" ); document.write( "\n" ); document.write( "You can easily construct a million other examples.\r
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