Câu hỏi của Nguyễn Thị Ánh Tuyết

Question

Tính tổng:

S=1/2+1/2^2+...+1/2^2019

Nguyễn Phạm Hồng Anh · Accepted Answer

$S=\frac{1}{2}+\frac{1}{2^2}+\frac{1}{2^3}+...+\frac{1}{2^{2019}}$

=> $2S=1+\frac{1}{2}+\frac{1}{2^2}+...+\frac{1}{2^{2018}}$

=> $S=1-\frac{1}{2^{2019}}$

Study well ! >_<

Câu trả lời:

$S=\frac{1}{2}+\frac{1}{2^2}+\frac{1}{2^3}+...+\frac{1}{2^{2019}}$

=> $2S=1+\frac{1}{2}+\frac{1}{2^2}+...+\frac{1}{2^{2018}}$

=> $S=1-\frac{1}{2^{2019}}$

Study well ! >_<