document.write( "Question 1165361: Given a function f of a real variable which satisfies the function defined by x*f(2-x)-2*f(x)=x^2+1 for all real x, determine f(x) in terms of x. \n" ); document.write( "
Algebra.Com's Answer #789880 by KMST(5328)\"\" \"About 
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Let's make \"system%28a=f%28x%29%2C+b=f%282-x%29%29\"
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\n" ); document.write( "When the variable is x, the equation is
\n" ); document.write( "\"x%2Af%282-x%29-2%2Af%28x%29=x%5E2%2B1\" , which we write in abbreviated form as
\n" ); document.write( "\"x%2Ab-2a=x%5E2%2B1\" (1)
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\n" ); document.write( "When the variable is 2-x, the equation is
\n" ); document.write( "\"%282-x%29%2Af%282-%282-x%29%29-2%2Af%282-x%29=%282-x%29%5E2%2B1\" , which we want to simplify as
\n" ); document.write( "\"%282-x%29%2Af%28x%29-2%2Af%282-x%29=4-4x%2Bx%5E2%2B1\" , and
\n" ); document.write( "\"%282-x%29%2Af%28x%29-2%2Af%282-x%29=x%5E2-4x%2B5\" , and abbreviate as
\n" ); document.write( "\"%282-x%29%2Aa-2b=x%5E2-4x%2B5\" (2)
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\n" ); document.write( "In (1) and (2), we have a system of equations on \"a\" and \"b\" :
\n" ); document.write( "\"system%28x%2Aa-2b=x%5E2-4x%2B5%2C-2a%2Bx%2Ab=x%5E2%2B1%29\" . Let's solve for \"a\" .
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\n" ); document.write( "Multiplying (2) times \"x%2F2\" we get \"%28%282x-x%5E2%29%2F2%29a-%28x%2F2%292b=%28x%2F2%29%28x%5E2-4x%2B5%29\" ,
\n" ); document.write( "which we simplify to
\n" ); document.write( "\"%28%28-x%5E2%2B2x%29%2F2%29a-x%2Ab=%28x%5E3-4x%5E2%2B5x%29%2F2\" ,
\n" ); document.write( "and add it to (1) to get
\n" ); document.write( "\"%28%28-x%5E2%2B2x%29%2F2%29a-2a=%28x%5E3-4x%5E2%2B5x%29%2F2%2Bx%5E2%2B1\" ,
\n" ); document.write( "\"%28%28-x%5E2%2B2x-4%29%2F2%29a=%28x%5E3-4x%5E2%2B5x%2B2x%5E2%2B2%29%2F2\"
\n" ); document.write( "\"-x%5E2%2B2x-4=-%28x%5E2-2x%2B4%29\" is not zero for any real number,
\n" ); document.write( "so we can divide by that expression to solve for \"a\"
\n" ); document.write( "\"%28-x%5E2%2B2x-4%29a=%28x%5E3-2x%5E2%2B5x%2B2%29\"
\n" ); document.write( "\"a=-%28x%5E3-2x%5E2%2B5x%2B2%29%2F%28x%5E2-2x%2B4%29\"
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\n" ); document.write( "The function is
\n" ); document.write( "\"highlight%28f%28x%29=-%28x%5E3-2x%5E2%2B5x%2B2%29%2F%28x%5E2-2x%2B4%29%29\" .
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