Chứng tỏ:
\(1+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{62}+\frac{1}{63}+\frac{1}{64}>4\)
Chứng tỏ rằng:
\(1\)+\(\frac{1}{2}\)+\(\frac{1}{3}\)+...+\(\frac{1}{62}\)+\(\frac{1}{63}\)+\(\frac{1}{64}\)\(>\)\(4\)
Chứng tỏ rằng:
\(1+\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+....+\frac{1}{63}+\frac{1}{64}>4\)
CHỨNG TỎ RẰNG :
1+\(\frac{1}{2}\)+\(\frac{1}{3}\)+....................+\(\frac{1}{62}\)+\(\frac{1}{63}\)+\(\frac{1}{64}\)
>4
cho:
a) A= 2+\(\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+....+\frac{1}{62}+\frac{1}{63}+\frac{1}{64}+\frac{1}{65}+\frac{1}{66}+\frac{1}{67}\)
chứng minh rằng A>5
b) B= \(\frac{1}{2^2}+\frac{1}{3^2}+\frac{1}{4^2}+...+\frac{1}{89^2}+\frac{1}{90^2}\)
chứng minh rằng \(\frac{40}{91}\)<B<1
CHỨNG MINH:
\(\frac{ }{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+\frac{1}{5}+...+\frac{1}{63}+\frac{1}{64}>3}\)
Chứng minh rằng
\(1-\frac{1}{2}+\frac{1}{3}-\frac{1}{4}+..+\frac{1}{121}-\frac{1}{122}+\frac{1}{123}=\frac{1}{62}+\frac{1}{63}+...+\frac{1}{122}\)-\(\frac{1}{123}\)
chứng minh rằng:a/ \(\frac{1}{4}+\frac{1}{16}+\frac{1}{36}+\frac{1}{64}+\frac{1}{100}+\frac{1}{144}+\frac{1}{196}< \frac{1}{2}\) \(\frac{1}{2}\)
b/\(\frac{1}{5}+\frac{1}{13}+\frac{1}{14}+\frac{1}{15}+\frac{1}{61}+\frac{1}{62}+\frac{1}{63}< \frac{1}{2}\)\(\frac{1}{2}\)
nhanh thì tích
chậm thì thôi
Chứng minh :\(1+\frac{1}{2}+\frac{1}{3}+........+\frac{1}{63}+\frac{1}{64}>4\)
