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³]R¬°¹ê¼Æ¶°¡A½T»{©Ò¦³¨ç¼Æf¡GR¡÷Rº¡¨¬¥H¤U©Ê½è¡G¹ï©ó¥ô·Nªº¹ê¼Æx¡By¦³
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ÃÒ©ú¡G¹ï©ó¥ô·Nªº¾ã¼Æx¡A¦³f¡Cf(x)=x¤Î[f(x)]2=x2¡C
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²{ÃÒ©ú¡Gf(1)=1©ÎªÌf(1)=-1¡C¥Ñf(1)2=12=1¡A©Ò¥Hf(1)=1©ÎªÌf(1)=-1¡C
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³Ì«ánÃÒ©ú¡Gf(x)¡Ýx©Îf(x)¡Ý-xµø¥Gf(1)=1©ÎªÌf(1)=-1¡C
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ÃÒ©ú¡G¹ï©ó¥ô·Nªº¾ã¼Æy¡A¦³f( 1+f(y) ) =1+y¡C
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³oÃDªº¥Dn«ä·Q¬O§âì¤èµ{ªº¥ª¦¡f( x f(x) +y) ¤¤ªº¶µxf(x)§R°£¡A
³Ì±`¨£ªº¤èªk¬O¦Ò¼{¡Gx=0¡A©ÎªÌ¿ï¨ú¾A¦XªºxȨϱof(x)=0¡C
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³]Z¬°¾ã¼Æ¶°¦X¡A¸Õ½T©w©Ò¦³¨ç¼Æf¡Bg¡GZ¡÷Zº¡¨¬¤U¦C±ø¥ó¡G
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¹ï©ó¥ô·Nªº¾ã¼Æx¡By¦³f( g(x) +y) =g( f(y) + x)¡F
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¥Ñ즡ÃÒ©ú¡Gf(g(x))=g(c+x)¡Bg(f(y))=f(y+d)¡C
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¦A§Q¥Î½Æ¦X¨ç¼Æªºµ²¦X«ß(g¡Cf)¡Cg=g¡C (f¡Cg)¡A±o
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±µµÛ¥Ñgªº³æ®g©Ê½è¤Î(ii)¡A±og(c+x)=f(d)+x¡C
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¥Ñ(iii)±og(x)=f(d)+x-c =x+M¡A¨ä¤¤M=f(d)-c¡C
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µM«á§âx´«¬°x-M¡A«hg(x-M)=x¡C§ây=0¡B¤Îx§ï¬°x-M¥N¤Jì¤èµ{¡A±o
f(x)=f(g(x-M)+0)=g(
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µù¡G³o°ÝÃDªºÃø³B¦b©ó¦³¨âÓ¥¼ª¾¨ç¼Æf©Mg¡A¨Ã§Q¥Îµ²¦X«ß¡C
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³]R¬°¹ê¼Æ¶°¡A¸Õ¨D¨ç¼Æf¡GR¡÷Rº¡¨¬µ¥¦¡¡G¹ï©ó¥ô·Nªº¹ê¼Æx¡By¦³f( f(x +y) )
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f(f(x))=f(x)+cf(x)=(1+c)f(x)¡C´«¥y¸Ü»¡¡A§Y
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f(z)=(1+c)z¡A¨ä¤¤z¦bRan(f)¡C
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³Ñ¤U¨ÓnÃÒ©ú¡G¹ï©ó¥ô·Nªº¹ê¼Æx¡A¦³f(x)=x¡C¥Ñ©ó(i)¡A±of(f(x))=f(x)¡C±q즡±of(x+y)=f(f(x+y))=f(x+y)+f(x)
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³]N={0, 1, 2, .... }¬°¦ÛµM¼Æ¶°¦X¡A½T©w©Ò¦³¨ç¼Æf¡GN¡÷Nº¡¨¬¤U¦C¨ç¼Æ¤èµ{¡G
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f(p)=[f( f(0) ) + f(0) ] -p =6-p¡F
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f(6-p)=[ f( f(p) ) +f(p) ]- (6-p)= 2p+6 -6 +p= 3p¡F
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f(3p) =[f( f(6-p) ) +f(6-p) ] -3p= 2(6-p) + 6 -3p=18-5p¡F
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f(18-5p)=[ f( f(3p) ) +f(3p) ] -(18-5p) = 2(3p) +6 -18+5p=11p -12¡F
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²q·Q¡G¹ï©Ò¦³¦ÛµM¼Æn¡A¦³f(2n)=2n+2¡C
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f(3)+f(5)=f(f(5))+f(5)=2(5)+6=16¡A§Yf(3)=13¡C¦A¥Ñì¨ç¼Æ¤èµ{¡A±o
f(13)=f(f(3))=[f( f(3) ) +f(3)] -13=[2(3)+6]-13= -1¡C³o¬O¤£¥i¯àªº¡A¦]¦¹q¤£¬O5¡F
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