Question

[Nguyễn Thị Thơ]

Chứng minh: 1/2² + 1/3² + 1/4²..... +1/2015² <1

Answer 1

[✓ ℍɠŞ_ŦƦùM $₦G ✓]

\(\frac{1}{2^2}+\frac{1}{3^2}+...+\frac{1}{100^2}<\frac{1}{1.2}+\frac{1}{2.3}+...+\frac{1}{99.100}\)

\(=1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+...+\frac{1}{99}-\frac{1}{100}=1-\frac{1}{100}<1\)

\(\Rightarrow\)ĐPCM

Answer 2

[Phạm Quỳnh Hương]

Cong Thanh sai dau bai rui