ÌâÄ¿ÄÚÈÝ
21£¨´ÓÒÔÏÂËĸöÌâÖÐÈÎÑ¡Á½¸ö×÷´ð£¬Ã¿Ìâ10·Ö£©
£¨1£©¼¸ºÎÖ¤Ã÷Ñ¡½²
ABÊÇ¡ÑOµÄÖ±¾¶£¬DΪ¡ÑOÉÏÒ»µã£¬¹ýµãD×÷¡ÑOµÄÇÐÏß½»ABÑÓ³¤ÏßÓÚC£¬ÈôDA=DC£¬ÇóÖ¤AB=2BC
£¨2£©¾ØÕóÓë±ä»»
ÔÚƽÃæÖ±½Ç×ø±êϵxOyÖУ¬A(0,0),B(-3,),C(-2,1),Éèk¡Ù0£¬k¡ÊR£¬M=,N=,µãA¡¢B¡¢CÔÚ¾ØÕóMN¶ÔÓ¦µÄ±ä»»Ïµõ½µãA1,B1,C1,¡÷A1B1C1µÄÃæ»ýÊÇ¡÷ABCÃæ»ýµÄ2±¶£¬ÇóʵÊýkµÄÖµ
£¨3£©²ÎÊý·½³ÌÓ뼫×ø±ê
ÔÚ¼«×ø±êϵÖУ¬Ô²¦Ñ=2cos¦ÈÓëÖ±Ïß3¦Ñcos¦È+4¦Ñsin¦È+a=0ÏàÇУ¬ÇóʵÊýaµÄÖµ
£¨4£©²»µÈʽ֤Ã÷Ñ¡½²
ÒÑ֪ʵÊýa,b¡Ý0£¬ÇóÖ¤£º
¡¾´ð°¸¡¿
¡¾½âÎö¡¿
Á·Ï°²áϵÁдð°¸
Ïà¹ØÌâÄ¿