Chứng minh rằng:
a)\(\frac{1}{1.2}+\frac{1}{3.4}+\frac{1}{5.6}< \frac{1}{1.2}+\frac{1}{3.4}+\frac{1}{5.6}+...+\frac{1}{99.100}\)
b)\(\frac{1}{1.2}+\frac{1}{3.4}+\frac{1}{5.6}+...+\frac{1}{99.100}< 1-\frac{1}{2.3}\)
Cần gấp, ai nhanh mik tick nha
a) A = 1/1.2+ 1/3.4+ 1/5.6+...+ 1/99.100
CMR: 7/12<A< 5/6
b) CMR: 1/1.2+ 1/3.4+ 1/5.6+...+1/49.50 = 1/26+ 1/27+ 1/28+...+1/50
CMR 7/12<1/1.2+1/3.4+1/5.6+...+1/99.100<5/6
Chứng minh 7/12< 1/1.2 + 1/3.4 +1/5.6 +...... + 1/99.100 <5/6
s=1/1.2+1/3.4+1/5.6+...+1/99.100
chứng minh s<5/6
Cho A=1/1.2+1/3.4+1/5.6+...+1/99.100,CMR:7/12<A<5/6
Cho A=1/1.2+1/3.4+1/5.6+...+1/99.100. Chứng tỏ rằng 17/12 < A < 5/6
Cho: A= 1/1.2+1/3.4+1/5.6+.....+1/99.100
CMR: 7/12<A<5/6.
Cho A=1/1.2 + 1/3.4 + 1/5.6 +...+1/99.100
CMR 7/12 < A<5/6
