Cho A= 1\1.2 + 1\3.4 + 1\5.6 + ... + 1\99.100
Chứng minh rằng: 7\12 < A < 5\6
CHỨNG MINH 7/12<A<5/6 với A=1/1.2+1/3.4+1/5.6+.....+1/99.100
Cho A = 1/1.2+1/3.4+1/5.6+...+1/99.100
a Chứng minh A= 1/51+1/52+1/53+...+1/100
b Chứng minh 7/12<A<5/6
chứng minh rằng:
\(\frac{7}{12}\)<A=\(\frac{1}{1.2}+\frac{1}{3.4}+\frac{1}{5.6}+...+\frac{1}{99.100}
Cho \(A=\frac{1}{1.2}+\frac{1}{3.4}+\frac{1}{5.6}+....\frac{1}{99.100}.\)Chứng minh rằng:
a.\(A=\frac{1}{51}+\frac{1}{52}+\frac{1}{53}+....+\frac{1}{100}.\)
b.\(\frac{7}{12}< A< \frac{5}{6}.\)
cho A=1/1.2+1/3.4+1/5.6+....+1/99.100 chung to rang A>7/12
Chứng minh:
\(\frac{7}{12}< \frac{1}{1.2}+\frac{1}{3.4}+\frac{1}{5.6}+...+\frac{1}{99.100}< \frac{5}{6}\)
Chứng minh rằng:
a) 1.2 - 1 phần 2! + 2.3 -1 phần 3! + 3.4 -1/4! + ... + 99.100 -1 /100! < 2
b) 1/1.2 + 1/3.4 + 1/5.6 + ... + 1/49.50 = 1/26 + 1/27 + 1/28 + ... + 1/50
\(A=\frac{1}{1.2}+\frac{1}{3.4}+\frac{1}{5.6}+...+\frac{1}{99.100}.\)
CM. \(\frac{5}{6}< A< \frac{7}{12}\)
