ÌâÄ¿ÄÚÈÝ
ÒÑÖªÊýÁÐ{an}ÖУ¬a1=1£¬ÇÒµãP£¨an£¬an+1£©ÔÚÖ±Ïßx-y+1=0ÉÏ¡£
£¨1£©ÇóÊýÁÐ{an}µÄͨÏʽ£»
£¨2£©Èôº¯Êý£¨n¡ÊN£¬ÇÒn¡Ý2£©£¬Çóº¯Êýf£¨n£©µÄ×îСֵ£»
£¨3£©Éèbn=£¬Sn±íʾÊýÁÐ{bn}µÄÇ°nÏîºÍ¡£ÊÔÎÊ£ºÊÇ·ñ´æÔÚ¹ØÓÚnµÄÕûʽg£¨n£©£¬Ê¹µÃS1+S2+S3+¡+Sn-1=£¨Sn-1£©¡¤g£¨n£©¶ÔÓÚÒ»Çв»Ð¡ÓÚ2µÄ×ÔÈ»Êýnºã³ÉÁ¢£¿ Èô´æÔÚ£¬Ð´³ög£¨n£©µÄ½âÎöʽ£¬²¢¼ÓÒÔÖ¤Ã÷£»Èô²»´æÔÚ£¬ÊÔ˵Ã÷ÀíÓÉ¡£
½â£º£¨1£©ÓɵãPÔÚÖ±Ïßx-y+1=0ÉÏ£¬¼´
£¬ÇÒ
£¬ÊýÁÐ{
}ÊÇÒÔ1ΪÊ×Ï1Ϊ¹«²îµÄµÈ²îÊýÁÐ
£¬
ͬÑùÂú×㣬ËùÒÔ
£¨2£©
ËùÒÔf£¨n£©Êǵ¥µ÷µÝÔö£¬¹Êf£¨n£©µÄ×îСֵÊÇf£¨2£©=
£¨3£©£¬¿ÉµÃ
£¬
¡¡£¬n¡Ý2 £¬
¹Ê´æÔÚ¹ØÓÚnµÄÕûʽg£¨x£©=n,ʹµÃ¶ÔÓÚÒ»Çв»Ð¡ÓÚ2µÄ×ÔÈ»Êýnºã³ÉÁ¢¡£

Á·Ï°²áϵÁдð°¸
Ïà¹ØÌâÄ¿
ÒÑÖªÊýÁÐ{an}ÖУ¬a1=1£¬2nan+1=£¨n+1£©an£¬ÔòÊýÁÐ{an}µÄͨÏʽΪ£¨¡¡¡¡£©
A¡¢
| ||
B¡¢
| ||
C¡¢
| ||
D¡¢
|