ÌâÄ¿ÄÚÈÝ

£¨2009•´óÁ¬¶þÄ££©£¨I£©ÒÑÖªº¯Êýf£¨x£©=x-
1
x
£¬x¡Ê(
1
4
£¬
1
2
)£¬P(x1£¬f(x1))£¬Q(x2£¬f(x2))ÊÇf(x)
ͼÏóÉϵÄÈÎÒâÁ½µã£¬ÇÒx1£¼x2£®
¢ÙÇóÖ±ÏßPQµÄбÂÊkPQµÄÈ¡Öµ·¶Î§¼°f£¨x£©Í¼ÏóÉÏÈÎÒ»µãÇÐÏßµÄбÂÊkµÄÈ¡Öµ·¶Î§£»
¢ÚÓÉ¢ÙÄãµÃµ½µÄ½áÂÛÊÇ£ºÈôº¯Êýf£¨x£©ÔÚ[a£¬b]ÉÏÓе¼º¯Êýf¡ä£¨x£©£¬ÇÒf£¨a£©¡¢f£¨b£©´æÔÚ£¬ÔòÔÚ£¨a£¬b£©ÄÚÖÁÉÙ´æÔÚÒ»µã¦Î£¬Ê¹µÃf¡ä£¨¦Î£©=
f(b)-f(a)
b-a
f(b)-f(a)
b-a
³ÉÁ¢£¨ÓÃa£¬b£¬f£¨a£©£¬f£¨b£©±íʾ£¬Ö»Ð´³ö½áÂÛ£¬²»±ØÖ¤Ã÷£©
£¨II£©É躯Êýg£¨x£©µÄµ¼º¯ÊýΪg¡ä£¨x£©£¬ÇÒg¡ä£¨x£©Îªµ¥µ÷µÝ¼õº¯Êý£¬g£¨0£©=0£®ÊÔÔËÓÃÄãÔÚ¢ÚÖеõ½µÄ½áÂÛÖ¤Ã÷£º
µ±x¡Ê£¨0£¬1£©Ê±£¬f£¨1£©x£¼g£¨x£©£®
·ÖÎö£º£¨I£©¢ÙÓÉÓÚf£¨x£©=x-
1
x
£¬x¡Ê£¨
1
4
£¬
1
2
£©£¬ÒÀÌâÒ⣬¿ÉÇóµÃÖ±ÏßPQµÄбÂÊkPQ=1-
1
x2x1
¡Ê£¨-15£¬-3£©£®¢ÚÒÀÌâÒ⣬ÔòÔÚ£¨a£¬b£©ÄÚÖÁÉÙ´æÔÚÒ»µã¦Î£¬Ê¹µÃf¡ä£¨¦Î£©=
f(b)-f(a)
b-a
£»
£¨II£©µ±x¡Ê£¨0£¬1£©£¬¸ù¾Ý£¨1£©ÖТڵĽáÂÛ£¬µÃµ½´æÔÚ¦Î1¡Ê£¨0£¬x£©£¬¦Î2¡Ê£¨x£¬1£©£¬Ê¹µÃg¡ä£¨¦Î1£©=
g(x)-g(0)
x-0
£¬g¡ä£¨¦Î2£©=
g(1)-g(x)
1-x
£¬ÔÙÀûÓÃg¡ä£¨x£©Îªµ¥µ÷µÝ¼õº¯Êý£¬g£¨0£©=0£¬¼´¿ÉÖ¤µÃg£¨1£©x£¼g£¨x£©£®
½â´ð£º½â£º£¨1£©¢ÙÖ±ÏßPQµÄбÂÊkPQ=
f(x2)-f(x1)
x2-x1
=1-
1
x2x1
£¬
ÓÉÓÚ
1
4
£¼x1£¼x2£¼
1
2
£¬ËùÒÔ-15£¼1-
1
x2x1
£¼-3£¬
¼´Ö±ÏßPQµÄбÂÊkPQ¡Ê£¨-15£¬-3£©£®¡­£¨2·Ö£©
ÓÉf¡ä£¨x£©=1-
1
x2
£¬ÓÖx¡Ê£¨
1
4
£¬
1
2
£©£¬ËùÒÔf¡ä£¨x£©¡Ê£¨-15£¬-3£©£¬
¼´f£¨x£©Í¼ÏóÉÏÈÎÒ»µãÇÐÏßµÄбÂÊkµÄÈ¡Öµ·¶Î§Îªk¡Ê£¨-15£¬-3£©£®¡­£¨4·Ö£©
¢Ú
f(b)-f(a)
b-a
£®¡­£¨6·Ö£©
£¨2£©µ±x¡Ê£¨0£¬1£©£¬¸ù¾Ý£¨1£©ÖТڵĽáÂÛ£¬µÃµ½´æÔÚ¦Î1¡Ê£¨0£¬x£©£¬¦Î2¡Ê£¨x£¬1£©£¬Ê¹µÃ
g¡ä£¨¦Î1£©=
g(x)-g(0)
x-0
£¬g¡ä£¨¦Î2£©=
g(1)-g(x)
1-x
£¬¡­£¨9·Ö£©
ÓÖg¡ä£¨x£©Îªµ¥µ÷µÝ¼õº¯Êý£¬ËùÒÔg¡ä£¨¦Î1£©£¾g¡ä£¨¦Î2£©£¬
¼´
g(x)-g(0)
x-0
£¾
g(1)-g(x)
1-x
£¬¶øg£¨0£©=0£¬
ËùÒÔ
g(x)
x
£¾
g(1)-g(x)
1-x
£¬
ÒòΪx¡Ê£¨0£¬1£©£¬ËùÒÔx£¾0£¬1-x£¾0
ËùÒÔg£¨1£©x£¼g£¨x£©£®¡­£¨12·Ö£©
µãÆÀ£º±¾Ì⿼²éÀûÓõ¼ÊýÑо¿º¯ÊýµÄµ¥µ÷ÐÔ£¬¿¼²éÖ±ÏßµÄбÂʼ°ÀûÓò»µÈʽȷ¶¨Ð±ÂÊÖ®·¶Î§£¬¿¼²éµ¼ÊýµÄ¼¸ºÎÒâÒå¼°×ÛºÏÓ¦Óã¬ÊôÓÚÄÑÌ⣮
Á·Ï°²áϵÁдð°¸
Ïà¹ØÌâÄ¿

Î¥·¨ºÍ²»Á¼ÐÅÏ¢¾Ù±¨µç»°£º027-86699610 ¾Ù±¨ÓÊÏ䣺58377363@163.com

¾«Ó¢¼Ò½ÌÍø