¼Çº¯Êýfn(x)=a•xn-1(a¡ÊR£¬n¡ÊN*)µÄµ¼º¯ÊýΪ
f
¡ä
n
(x)
£¬ÒÑÖª
f
¡ä
3
(2)=12
£®
£¨¢ñ£©ÇóaµÄÖµ£®
£¨¢ò£©É躯Êýgn(x)=fn(x)-n2Inx£¬ÊÔÎÊ£ºÊÇ·ñ´æÔÚÕýÕûÊýnʹµÃº¯Êýgn£¨x£©ÓÐÇÒÖ»ÓÐÒ»¸öÁãµã£¿Èô´æÔÚ£¬ÇëÇó³öËùÓÐnµÄÖµ£»Èô²»´æÔÚ£¬Çë˵Ã÷ÀíÓÉ£®
£¨¢ó£©ÈôʵÊýx0ºÍm£¨m£¾0£¬ÇÒm¡Ù1£©Âú×㣺
f
¡ä
n
(x0)
f
¡ä
n+1
(x0)
=
fn(m)
fn+1(m)
£¬ÊԱȽÏx0ÓëmµÄ´óС£¬²¢¼ÓÒÔÖ¤Ã÷£®
·ÖÎö£º£¨¢ñ£©Ö±½ÓÓÉ
f
¡ä
3
(2)=12
ÁÐʽÇóaµÄÖµ£»
£¨¢ò£©Çó³öº¯ÊýµÄµ¼º¯Êý£¬Çó³öµ¼º¯ÊýµÄÁãµã£¬Óɵ¼º¯ÊýµÄÁãµã¶Ô¶¨ÒåÓò·Ö¶Î£¬Óɵ¼º¯ÊýµÄ·ûºÅÅжÏÔ­º¯ÊýµÄµ¥µ÷ÐÔ£¬Çó³öÔ­º¯ÊýµÄ×îÖµ£¬¸ù¾Ý×îÖµ·ÖÎöº¯ÊýµÄÁãµã¸öÊý£»
£¨¢ó£©Çó³öfn¡ä(x)=n•xn-1£¬´úÈë
f
¡ä
n
(x0)
f
¡ä
n+1
(x0)
=
fn(m)
fn+1(m)
£¬½â³öx0£¬°Ñx0Óëm×÷²îºó¹¹Ô츨Öúº¯Êý£¬Çó³ö¸¨Öúº¯ÊýµÄµ¼º¯Êý£¬Óɸ¨Öúº¯ÊýµÄµ¥µ÷ÐÔ¼´¿ÉÖ¤Ã÷x0ÓëmµÄ²îÓë0µÄ´óС¹Øϵ£¬Ôò½áÂ۵õ½Ö¤Ã÷£®
½â´ð£º½â£º£¨¢ñ£©f3¡ä(x)=3ax2£¬ÓÉf3¡ä(2)=12£¬µÃa=1£»
£¨¢ò£©gn(x)=xn-n2lnx-1£¬gn¡ä(x)=n•xn-1-
n2
x
=
n(xn-n)
x
£¬
¡ßx£¾0£¬Áîgn¡ä(x)=0£¬µÃx=
nn
£®
µ±x£¾
nn
ʱ£¬gn¡ä(x)£¾0£¬gn£¨x£©ÊÇÔöº¯Êý£»
µ±0£¼x£¼
nn
ʱ£¬gn¡ä(x)£¼0£¬gn£¨x£©ÊǼõº¯Êý£»
ËùÒÔµ±x=
nn
ʱ£¬gn£¨x£©Óм«Ð¡Öµ£¬Ò²ÊÇ×îСֵ£¬gn(
nn
)=n-nlnn-1
£®
µ±x¡ú0ʱ£¬gn£¨x£©¡ú+¡Þ£»
µ±x¡ú+¡Þʱ£¬£¨¿ÉÈ¡x=e£¬e2£¬e3£¬¡­ÌåÑ飩£¬gn£¨x£©¡ú+¡Þ£®
µ±n¡Ý3ʱ£¬gn(
nn
)=n(1-lnn)-1£¼0
£¬º¯Êýgn£¨x£©ÓÐÁ½¸öÁãµã£»
µ±n=2ʱ£¬gn(
nn
)=-2ln2+1£¼0
£¬º¯Êýgn£¨x£©ÓÐÁ½¸öÁãµã£»
µ±n=1ʱ£¬gn(
nn
)=0
£¬º¯Êýgn£¨x£©Ö»ÓÐÒ»¸öÁãµã£»
×ÛÉÏËùÊö£¬´æÔÚn=1ʹµÃº¯Êýgn£¨x£©ÓÐÇÒÖ»ÓÐÒ»¸öÁãµã£®
£¨¢ó£©fn¡ä(x)=n•xn-1£¬
¡ß
fn¡ä(x0)
fn-1¡ä(x0)
=
fn(m)
fn-1(m)
£¬¡à
nx0n-1
(n+1)x0n
=
mn-1
mn+1-1
£®
½âµÃx0=
n(mn+1-1)
(n+1)(mn-1)
£¬
Ôòx0-m=
-mn+1+m(n+1)-n
(n+1)(mn-1)
£¬
µ±m£¾1ʱ£¬£¨n+1£©£¨mn-1£©£¾0£¬Éèh£¨x£©=-xn+1+x£¨n+1£©-n£¨x¡Ý1£©£¬
Ôòh¡ä£¨x£©=-£¨n+1£©xn+n+1=-£¨n+1£©£¨xn-1£©¡Ü0£¨µ±ÇÒ½öµ±x=1ʱȡµÈºÅ£©£¬
ËùÒÔh£¨x£©ÔÚ[1£¬+¡Þ£©ÉÏÊǼõº¯Êý£¬
ÓÖÒòΪm£¾1£¬ËùÒÔh£¨m£©£¼h£¨1£©=0£¬ËùÒÔx0-m£¼0£¬ËùÒÔx0£¼m£®
µ±0£¼m£¼1ʱ£¬£¨n+1£©£¨mn-1£©£¼0£¬Éèh£¨x£©=-xn+1+x£¨n+1£©-n£¨0£¼x¡Ü1£©£¬
Ôòh¡ä£¨x£©=-£¨n+1£©xn+n+1=-£¨n+1£©£¨xn-1£©¡Ý0£¨µ±ÇÒ½öµ±x=1ʱȡµÈºÅ£©£¬
ËùÒÔh£¨x£©ÔÚ£¨0£¬1]ÉÏÊÇÔöº¯Êý£¬ÓÖÒòΪ0£¼m£¼1£¬ËùÒÔh£¨m£©£¼h£¨1£©=0£¬ËùÒÔx0-m£¾0£¬
ËùÒÔx0£¾m£®
×ÛÉÏËùÊö£¬µ±m£¾1£¬x0£¼m£®µ±0£¼m£¼1ʱ£¬x0£¾m£®
µãÆÀ£º±¾Ì⿼²éÁ˵¼ÊýÔÚ×î´óÖµ×îСֵÖеÄÓ¦Ó㬿¼²éÁË·ÖÀàÌÖÂÛµÄÊýѧ˼Ïë·½·¨£¬ÑµÁ·Á˹¹Ô캯Êý·¨½øÐв»µÈʽµÄ´óС±È½Ï£¬ÊÇÓÐÒ»¶¨ÄѶÈÌâÄ¿£®
Á·Ï°²áϵÁдð°¸
Ïà¹ØÏ°Ìâ

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£º

ÒÑÖªº¯Êýfn(x)=
ln(x+n)-n
x+n
+
1
n(n+1)
£¨ÆäÖÐnΪ³£Êý£¬n¡ÊN*£©£¬½«º¯Êýfn£¨x£©µÄ×î´óÖµ¼ÇΪan£¬ÓÉan¹¹³ÉµÄÊýÁÐ{an}µÄÇ°nÏîºÍ¼ÇΪSn£®
£¨¢ñ£©ÇóSn£»
£¨¢ò£©Èô¶ÔÈÎÒâµÄn¡ÊN*£¬×Ü´æÔÚx¡ÊR+ʹ
x
ex-1
+a=an
£¬ÇóaµÄÈ¡Öµ·¶Î§£»
£¨¢ó£©±È½Ï
1
en+1+e•n
+fn(en)
ÓëanµÄ´óС£¬²¢¼ÓÒÔÖ¤Ã÷£®

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£º

ÒÑÖª¶¨ÒåÔÚʵÊý¼¯Éϵĺ¯Êýfn(x)=xn£¬£¨x¡ÊN*£©£¬Æäµ¼º¯Êý¼ÇΪfn¡ä£¨x£©£¬ÇÒÂú×ãfn¡ä[ax1+(1-a)x2]  =
f2(x2)-f2(x1x2-x1
£¬ÆäÖÐa£¬x1£¬x2Ϊ³£Êý£¬x1¡Ùx2£®É躯Êýg£¨x£©=f1£¨x£©+mf2£¨x£©-lnf3£¨x£©£¬£¨m¡ÊRÇÒm¡Ù0£©£®
£¨¢ñ£©ÇóʵÊýaµÄÖµ£»
£¨¢ò£©Èôº¯Êýg£¨x£©ÎÞ¼«Öµµã£¬Æäµ¼º¯Êýg¡ä£¨x£©ÓÐÁãµã£¬ÇómµÄÖµ£»
£¨¢ó£©Çóº¯Êýg£¨x£©ÔÚx¡Ê[0£¬a]µÄͼÏóÉÏÈÎÒ»µã´¦µÄÇÐÏßбÂÊkµÄ×î´óÖµ£®

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£º

ÒÑÖª¶¨ÒåÔÚʵÊý¼¯Éϵĺ¯Êýfn(x)=xn£¬(n¡ÊN*)£¬Æäµ¼º¯Êý¼ÇΪfn¡ä(x)£¬ÇÒÂú×ãf2¡ä[ax1+(1-a)x2]=
f2(x2)-f2(x1)x2-x1
£¬ÆäÖÐa¡¢x1¡¢x2Ϊ³£Êý£¬x1¡Ùx2£®É躯Êýg£¨x£©=f1£¨x£©+mf2£¨x£©-lnf3£¨x£©£¬£¨m¡ÊRÇÒm¡Ù0£©£®
£¨¢ñ£©ÇóʵÊýaµÄÖµ£»
£¨¢ò£©Èôm=1£¬Çóº¯Êýg£¨x£©µÄµ¥µ÷Çø¼ä£»
£¨¢ó£©Çóº¯Êýg£¨x£©ÔÚx¡Ê[0£¬a]µÄͼÏóÉÏÈÎÒ»µã´¦µÄÇÐÏßбÂÊkµÄ×î´óÖµ£®

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º2012½ì¹ã¶«Ê¡µç°×Ë®¶«ÖÐѧ¸ßÈýÉÏѧÆÚµÚÈý´ÎÔ¿¼ÎÄ¿ÆÊýѧ ÌâÐÍ£º½â´ðÌâ

£¨±¾Ð¡ÌâÂú·Ö14·Ö£©ÒÑÖª¶¨ÒåÔÚʵÊý¼¯Éϵĺ¯Êýfn(x)=xn£¬n¡ÊN*£¬Æäµ¼º¯Êý¼ÇΪ£¬ÇÒÂú×㣬a£¬x1£¬x2Ϊ³£Êý,x1¡Ùx2£®
(1)ÊÔÇóaµÄÖµ£»
(2)¼Çº¯Êý£¬x¡Ê£¨0£¬e]£¬ÈôF(x)µÄ×îСֵΪ6£¬ÇóʵÊýbµÄÖµ£»
(3)¶ÔÓÚ(2)ÖеÄb£¬É躯Êý£¬A(x1£¬y1)£¬B(x2£¬y2)(x1<x2)ÊǺ¯Êýg(x)ͼÏóÉÏÁ½µã£¬Èô£¬ÊÔÅжÏx0£¬x1£¬x2µÄ´óС£¬²¢¼ÓÒÔÖ¤Ã÷£®

²é¿´´ð°¸ºÍ½âÎö>>

ͬ²½Á·Ï°²á´ð°¸