document.write( "Question 40413: 8. If f(x)= (ax-b)/c and f(f(x))=x for all x, then which of the following must be true?
\n" ); document.write( "I. |a| = |c|
\n" ); document.write( "II. a = 0
\n" ); document.write( "III. b>0
\n" ); document.write( "Answer. I and II only
\n" ); document.write( "The book has the solution but I can't seem to understand. Perhaps u can explain it in another way? thank u \n" ); document.write( "

Algebra.Com's Answer #26155 by venugopalramana(3286) $\"\"$ $\"About$

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Polynomials-and-rational-expressions/40413 (2006-06-02 00:44:45): 8. If f(x)= (ax-b)/c and f(f(x))=x for all x, then which of the following must be true?
\n" ); document.write( "I. |a| = |c|
\n" ); document.write( "II. a = 0
\n" ); document.write( "III. b>0
\n" ); document.write( "Answer. I and II only
\n" ); document.write( "The book has the solution but I can't seem to understand. Perhaps u can explain it in another way? thank u
\n" ); document.write( "0 solutions
\n" ); document.write( "LET F(X)=Y=(AX-B)/C
\n" ); document.write( "SO…F(F(X))=F(Y)=(AY-B)/C=X
\n" ); document.write( "CX=AY-B=A(AX-B)/C -B = (A^2X-AB-BC)/C
\n" ); document.write( "C^2X=A^2X-AB-BC…..FOR THIS TO BE TRUE FOR ALL VALUES OF X ,IT SHOULD BE AN IDENTITY..HENCE COEFFICIENTS OF CORRESPONDING TERMS ARE EQUAL
\n" ); document.write( "COEFF.OF X =C^2=A^2…………………….C=+ OR -A OR …|A|=|C|
\n" ); document.write( "CONSTANT TERM =0=-AB-BC=-B(A+C)…….B=0 OR A=-C
\n" ); document.write( "SO THE ANSWER IS A=-C…OR……B=0&|A|=|C| \n" ); document.write( "

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