\(\frac{1}{201}+\frac{1}{202}+...+\frac{1}{400}>\frac{1}{400}.200=\frac{200}{400}=\frac{1}{2}\)
=> điều phải chứng minh.
Đinh Tuấn Việt thì lúc nào cũng giỏi rồi
Chung to rang: 1/201+1/202+...+1/399+1/400>1/2
chung to 1/201+1/202+......+1/399+1/400>1/2
Chứng tỏ rằng: 1/201+1/202+....+1/399+1/400 >1/2
\(CMR:\frac{1}{201}+\frac{1}{202}+....+\frac{1}{399}+\frac{1}{400}>\frac{1}{2}\)
Chứng minh rằng:
1/201+ 1/202+...+ 1/399+ 1/400>1/2
1<1/5+ 1/6+...+1/16+ 1/17<2
chứng tỏ rằng :
a) 1/201 + 1/202 + 1/203+....+ 1/400 > 1/2
b) 1/201 + 1/202 + 1/203+....+ 1/400 < 1
CMR : \(\frac{1}{201}\) + \(\frac{1}{202}\) + ... + \(\frac{1}{399}\) + \(\frac{1}{400}\) > \(\frac{1}{2}\)
A=1/2+3/4+5/6+........+199/200
chung to rang A^2<1/201
cho A=1/2.3/4.5/6.7/8.....199/200
chung to rang A2<1/201
