Câu hỏi 3
Rút gọn biểu thức
$$\left(1+\frac1i+\frac1{i^2}+\ldots+\frac1{i^{2014}}\right)^2.$$
$$\left(1+\frac1i+\frac1{i^2}+\ldots+\frac1{i^{2014}}\right)^2.$$
MathNet 2014 Câu hỏi 3
Math Olympiad Vault · MathNet 2014
Math Olympiad Vault · MathNet 2014