首页 > 留学知识库

问题: 已知

已知f(n)={n-3 (n=10)
{f[f(n+5)] (n<10)求f(9)的值

解答:

已知f(n)={n-3..........n≥10
     {f[f(n+5)]....n<10
求f(9)的值

f(9)=f(f(9+5))=f(f(14))=f(14-3)=f(11)=f(11-3)=f(8)=
  =f(f(8+5))=f(f(13))=f(13-3)=f(10)=7