3Â¥: Originally posted by Á¢ÃÔÌØ at 2017-07-20 08:24:14
½«1+1/a_k±ä³É\frac{a_{k+1}}{(k+1)a_k}, È»ºóµÃµ½³Ë»ýΪ\frac{a_{n+1}}{(n+1)!} ¼ÆËãµÃ\frac{a_{n+1}}{(n+1)!}=\frac{a_n}{n!}+\frac{1}{n!}=\frac{a_{n-1}}{(n-1}!}+\frac{1}{(n-1)!}+\frac{1}{n!}=\cdots£¬ÒÀ´ÎµÝ ...

3Â¥: Originally posted by Á¢ÃÔÌØ at 2017-07-20 08:24:14
½«1+1/a_k±ä³É\frac{a_{k+1}}{(k+1)a_k}, È»ºóµÃµ½³Ë»ýΪ\frac{a_{n+1}}{(n+1)!} ¼ÆËãµÃ\frac{a_{n+1}}{(n+1)!}=\frac{a_n}{n!}+\frac{1}{n!}=\frac{a_{n-1}}{(n-1}!}+\frac{1}{(n-1)!}+\frac{1}{n!}=\cdots£¬ÒÀ´ÎµÝ ...