ÒÑÖªÊýÁÐ{an}µÄÇ°nÏîºÍSn=a£Û2£­()n£­1£Ý£­b£Û2£­(n+1)()n£­1£Ý(n=1,2,¡­),ÆäÖÐa¡¢bÊÇ·ÇÁã³£Êý,Ôò´æÔÚÊýÁÐ{xn}¡¢{yn}ʹµÃ(    )

A.an=xn+yn,ÆäÖÐ{xn}ΪµÈ²îÊýÁÐ,{yn}ΪµÈ±ÈÊýÁÐ

B.an=xn+yn,ÆäÖÐ{xn}ºÍ{yn}¶¼ÎªµÈ²îÊýÁÐ

C.an=xn¡¤yn,ÆäÖÐ{xn}ΪµÈ²îÊýÁÐ,{yn}ΪµÈ±ÈÊýÁÐ

D.an=xn¡¤yn,ÆäÖÐ{xn}ºÍ{yn}¶¼ÎªµÈ±ÈÊýÁÐ

½âÎö:µ±n¡Ý2ʱ,an=Sn£­Sn£­1=a£Û()n£­2£­()n£­1£Ý£­b£Ûn()n£­2£­(n+1)()n£­1£Ý=(a+b£­bn)¡¤()n£­1.

Áîxn=a+b£­bn,yn=()n£­1Ò×Öª{xn}ΪµÈ²îÊýÁÐ,{yn}ΪµÈ±ÈÊýÁÐ.

´ð°¸:C

Á·Ï°²áϵÁдð°¸
Ïà¹ØÏ°Ìâ

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£º

19¡¢ÒÑÖªÊýÁÐ{an}µÄÇ°nÏîºÍSn=n2£¨n¡ÊN*£©£¬ÊýÁÐ{bn}ΪµÈ±ÈÊýÁУ¬ÇÒÂú×ãb1=a1£¬2b3=b4
£¨1£©ÇóÊýÁÐ{an}£¬{bn}µÄͨÏʽ£»
£¨2£©ÇóÊýÁÐ{anbn}µÄÇ°nÏîºÍ£®

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£º

ÒÑÖªÊýÁÐ{an}µÄÇ°nÏîºÍSn=an2+bn£¨a¡¢b¡ÊR£©£¬ÇÒS25=100£¬Ôòa12+a14µÈÓÚ£¨¡¡¡¡£©
A¡¢16B¡¢8C¡¢4D¡¢²»È·¶¨

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£º

ÒÑÖªÊýÁÐ{an}µÄÇ°nÏîºÍSn=n2+n+1£¬ÄÇôËüµÄͨÏʽΪan=
 
£®

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£º

13¡¢ÒÑÖªÊýÁÐ{an}µÄÇ°nÏîºÍΪSn=3n+a£¬Èô{an}ΪµÈ±ÈÊýÁУ¬ÔòʵÊýaµÄֵΪ
-1
£®

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£º

ÒÑÖªÊýÁÐ{an}µÄÇ°nÏîºÍSnÂú×ãSn+1=kSn+2£¬ÓÖa1=2£¬a2=1£®
£¨1£©ÇókµÄÖµ¼°Í¨Ïʽan£®
£¨2£©ÇóSn£®

²é¿´´ð°¸ºÍ½âÎö>>

ͬ²½Á·Ï°²á´ð°¸