已知数列C(n+1)=5Cn+n,C1=0,依次代入Cn能否得到通项公式:Cn=(5^n-4n-1)/16呢?请分析一下,
问题描述:
已知数列C(n+1)=5Cn+n,C1=0,依次代入Cn能否得到通项公式:Cn=(5^n-4n-1)/16呢?请分析一下,
答
c(n+1) = 5c(n) + n,c(n+1) + (n+1)x + y = 5[c(n) + nx + y] = 5c(n) + 5nx + 5y,c(n+1) = 5c(n) + 4nx + 4y - x.x = 1/4,0 = 4y-x,y = x/4 = 1/16.c(n+1) + (n+1)/4 + 1/16 = 5c(n) + n + (n+1)/4 + 1/16 = 5c(n) ...