Chứng minh:
\(1+\frac{1}{2^2}+\frac{1}{3^2}+\frac{1}{4^2}+....+\frac{1}{n^2}<2-\frac{1}{n}\)
Chứng minh:
\(A=1+\frac{1}{2^2}+\frac{1}{3^2}+\frac{1}{4^2}+......+\frac{1}{n^2}<2-\frac{1}{n}\)
Cho n>=2 .Chứng minh:\(\frac{1}{2}
Chứng minh:
a, M= \(\frac{1}{2^2}+\frac{1}{3^2}+\frac{1}{4^2}+...+\frac{1}{n^2}< 1\)
b, \(\frac{1}{6}< \frac{1}{5^2}+\frac{1}{6^2}+\frac{1}{7^2}+...+\frac{1}{100^2}< \frac{1}{4}\)
\(\frac{1}{2^2}+\frac{1}{2^3}+\frac{1}{2^4}+\frac{1}{2^5}+.........+\frac{1}{2^n}\)
chứng minh tổng trên < 1
Chứng minh:\(\frac{1}{1^2}+\frac{1}{2^2}+\frac{1}{3^2}+\frac{1}{4^2}+........+\frac{1}{99^2}+\frac{1}{100^2}< 1\frac{3}{4}\)
Chứng minh
\(\frac{1}{2^{2+}}+\frac{1}{2^3}+\frac{1}{2^4}+........+\frac{1}{2^n}<1\)