Question

Chứng tỏ:

\(\frac{1}{2}+\frac{1}{3}+...+\frac{1}{63}>2\)

Giải chi tiết giúp mk nka

Answer 1

1/2=1/2
1/3+1/4>1/4+1/4=1/2
1/5+…+1/8>4*1/8=1/2
1/9+…+1/16>8*1/16=1/2
1/2+1/3+1/4+…+1/16>4*1/2=2
1/2+1/3+1/4+…+1/63>1/2+1/3+1/4+…+1/16
=>  1/2+1/3+…+1/63>2

t i c k nhé !! 5756876876978080

Answer 2

Ta có:

\(\frac{1}{2}=\frac{1}{2}\)

\(\frac{1}{3}+\frac{1}{4}>\frac{1}{4}+\frac{1}{4}=\frac{1}{2}\)

\(\frac{1}{5}+...+\frac{1}{8}>4.\frac{1}{8}=\frac{1}{2}\)

\(\frac{1}{9}+...+\frac{1}{16}>8.\frac{1}{16}=\frac{1}{2}\)

\(\frac{1}{2}+\frac{1}{3}+...+\frac{1}{16}>4.\frac{1}{2}=2\)

\(\frac{1}{2}+\frac{1}{3}+...+\frac{1}{63}>\frac{1}{2}+\frac{1}{3}+...+\frac{1}{16}\)

\(\Rightarrow\frac{1}{2}+\frac{1}{3}+...+\frac{1}{63}>2\)

Answer 3

\(\text{Ta có: }\)

\(\frac{1}{2}=\frac{1}{2}\)

\(\frac{1}{3}+\frac{1}{4}>\frac{1}{4}+\frac{1}{4}=\frac{1}{2}\)

\(\frac{1}{5}+...+\frac{1}{8}>4.\frac{1}{8}=\frac{1}{2}\)

\(\frac{1}{9}+...+\frac{1}{16}>8.\frac{1}{16}=\frac{1}{2}\)

\(\frac{1}{2}+\frac{1}{3}+...+\frac{1}{16}>4.\frac{1}{2}=2\)

\(\frac{1}{2}+\frac{1}{3}+...+\frac{1}{63}>\frac{1}{2}+\frac{1}{3}+...+\frac{1}{16}\)

\(\frac{1}{2}+\frac{1}{3}+...+\frac{1}{63}>\frac{1}{2}+\frac{1}{3}+...+\frac{1}{16}\)