计算：lim正无穷1+1/3+1/9+.+1/3^n-1/1+1/2+1/4+...+1/2^n-1rtttttttttttttttttt

计算：lim正无穷1+1/3+1/9+.+1/3^n-1/1+1/2+1/4+...+1/2^n-1rtttttttttttttttttt
计算：lim正无穷1+1/3+1/9+.+1/3^n-1/1+1/2+1/4+...+1/2^n-1
rtttttttttttttttttt

计算：lim正无穷1+1/3+1/9+.+1/3^n-1/1+1/2+1/4+...+1/2^n-1rtttttttttttttttttt
分子,a1=1,q=1/3,有n项
所以=1*[1-(1/3)^n]/(1-1/3)=3/2-3/2*(1/3)^n
同理,分母=2-2*(1/2)^n
n→+∞
因为0