lim(n->∞) Fn/F(n+1)
=lim(n->∞) {[(1+√5)/2]^(n+1)-[(1-√5)/2]^(n+1)}/{[(1+√5)/2]^(n+2)-[(1-√5)/2]^(n+2)}
分子分母同除以[(1+√5)/2]^(n+1)
=lim(n->∞) {1-[(1-√5)/(1+√5)]^(n+1)}/{(1+√5)/2-[(1-√5)/(1+√5)]^(n+1)*(1-√5)/2}
=(1-0)/[(1+√5)/2-0]
=2/(1+√5)
=(√5-1)/2
题目不完整吧,要求什么?