(1-1÷2)(1-1÷3)(1-1÷4)...(1-1÷n)
问题描述:
(1-1÷2)(1-1÷3)(1-1÷4)...(1-1÷n)
答
(1-1÷2)(1-1÷3)(1-1÷4)...(1-1÷n)=(1-1/2)(1+1/2)(1-1/3)(1+1/3)...(1-1/n)(1+1/n)=1/2*3/2*2/3*...*n-1/n*n+1/n=1/2*n+1/n=n+1/2n