ÌâÄ¿ÄÚÈÝ
ÒÑÖª£ºÔÚ¾ØÐÎAOBCÖУ¬OB£½4£¬OA£½3£¬·Ö±ðÒÔOB¡¢OAËùÔÚÖ±ÏßΪxÖáºÍyÖᣬ½¨Á¢ÈçͼËùʾµÄƽÃæÖ±½Ç×ø±êϵ£¬FÊDZßBCÉϵÄÒ»¸ö¶¯µã£¨²»ÓëB¡¢CÖغϣ©£¬¹ýFµãµÄ·´±ÈÀýº¯Êý
£¨k£¾0£©µÄͼÏóÓëAC±ß½»ÓÚµãE.
£¨1£©ÇóÖ¤£º¡÷AOEÓë¡÷BOFµÄÃæ»ýÏàµÈ.
£¨2£©¼ÇS£½S¡÷OEF£S¡÷ECF£¬Çóµ±kΪºÎֵʱ£¬SÓÐ×î´óÖµ£¬×î´óֵΪ¶àÉÙ£¿
£¨3£©Çë̽Ë÷£ºÊÇ·ñ´æÔÚÕâÑùµÄµãF£¬Ê¹µÃ½«¡÷CEFÑØEF¶ÔÕÛºó£¬CµãÇ¡ºÃÂäÔÚOBÉÏ£¿Èô´æÔÚ£¬ÇëÖ±½Óд³öµãFµÄ×ø±ê£¬Èô²»´æÔÚ£¬Çë˵Ã÷ÀíÓÉ.


£¨1£©ÇóÖ¤£º¡÷AOEÓë¡÷BOFµÄÃæ»ýÏàµÈ.
£¨2£©¼ÇS£½S¡÷OEF£S¡÷ECF£¬Çóµ±kΪºÎֵʱ£¬SÓÐ×î´óÖµ£¬×î´óֵΪ¶àÉÙ£¿
£¨3£©Çë̽Ë÷£ºÊÇ·ñ´æÔÚÕâÑùµÄµãF£¬Ê¹µÃ½«¡÷CEFÑØEF¶ÔÕÛºó£¬CµãÇ¡ºÃÂäÔÚOBÉÏ£¿Èô´æÔÚ£¬ÇëÖ±½Óд³öµãFµÄ×ø±ê£¬Èô²»´æÔÚ£¬Çë˵Ã÷ÀíÓÉ.

£¨1£©Ö¤Ã÷£ºÉèE£¨x1£¬y1£©,F(x2£¬y2)£¬¡÷AOEºÍ¡÷FOBµÄÃæ»ý·Ö±ðΪS1¡¢S2£¬

ÓÉÌâÒâµÃ
£¬
¡à
£¬¡¡
¡àS1£½S2¡¡£¬¼´¡÷AOEºÍ¡÷FOBµÄÃæ»ýÏàµÈ.
£¨2£©ÓÉÌâÒâÖª£ºE¡¢FÁ½µã×ø±ê·Ö±ðΪE£¨
£¬3£©¡¢F£¨4£¬
£©
S¡÷ECF£½
EC¡¤CF£½
£¨4£
£©£¨3£
£©
S¡÷EDF£½S¾ØÐÎAOBC£S¡÷AOE£S¡÷ECF£½12£
k£
k£S¡÷ECF
S£½S¡÷OEF£S¡÷ECF£½12£k£2 S¡÷ECF
£½12£k£2¡Á
£¨4£
£©£¨3£
£©
S£½
k2+k£¬
µ±k=6ʱ£¬SÓÐ×î´óÖµ3£®
£¨3£©´æÔÚ·ûºÏÌõ¼þµÄµãF£¬ËüµÄ×ø±êΪ£¨4£¬
£©

ÓÉÌâÒâµÃ


¡à


¡àS1£½S2¡¡£¬¼´¡÷AOEºÍ¡÷FOBµÄÃæ»ýÏàµÈ.
£¨2£©ÓÉÌâÒâÖª£ºE¡¢FÁ½µã×ø±ê·Ö±ðΪE£¨


S¡÷ECF£½




S¡÷EDF£½S¾ØÐÎAOBC£S¡÷AOE£S¡÷ECF£½12£


S£½S¡÷OEF£S¡÷ECF£½12£k£2 S¡÷ECF
£½12£k£2¡Á



S£½

µ±k=6ʱ£¬SÓÐ×î´óÖµ3£®
£¨3£©´æÔÚ·ûºÏÌõ¼þµÄµãF£¬ËüµÄ×ø±êΪ£¨4£¬

£¨1£©·Ö±ðÓõãE£¬FµÄ×ø±ê±íʾ³ö¡÷AOEÓë¡÷FOBµÄÃæ»ý£¬ÔÙÓÃS1£½S2£¬½øÐÐÇó½â£»
£¨2£©Ó¦·Ö±ðÓþØÐÎÃæ»ýºÍÄÜÓÃͼÖеĵã±íʾ³öµÄÈý½ÇÐεÄÃæ»ý±íʾ³öËùÇóµÄÃæ»ý£¬ÀûÓöþ´Îº¯ÊýÇó³ö×îÖµ¼´¿É£»
£¨3£©ÓÉ£¨2£©µãFµÄ×Ý×ø±êÒÑÇó£¬ÀûÓÃÕÛµþÒÔ¼°ÏàËÆÇóµÃµãFµÄºá×ø±ê¼´¿ÉµÃ³ö´ð°¸£®
£¨2£©Ó¦·Ö±ðÓþØÐÎÃæ»ýºÍÄÜÓÃͼÖеĵã±íʾ³öµÄÈý½ÇÐεÄÃæ»ý±íʾ³öËùÇóµÄÃæ»ý£¬ÀûÓöþ´Îº¯ÊýÇó³ö×îÖµ¼´¿É£»
£¨3£©ÓÉ£¨2£©µãFµÄ×Ý×ø±êÒÑÇó£¬ÀûÓÃÕÛµþÒÔ¼°ÏàËÆÇóµÃµãFµÄºá×ø±ê¼´¿ÉµÃ³ö´ð°¸£®

Á·Ï°²áϵÁдð°¸
Ïà¹ØÌâÄ¿