\(\frac{1}{51}+\frac{1}{52}+...+\frac{1}{100}>\frac{1}{100}+\frac{1}{100}+\frac{1}{100}+...+\frac{1}{100}=\frac{1}{100}.50=\frac{1}{2}\)
Vậy \(\frac{1}{51}+\frac{1}{52}+...+\frac{1}{100}>\frac{1}{2}\)
\(\frac{1}{51}+\frac{1}{52}+...+\frac{1}{100}
Chứng minh :(1+1/3+1/5+...+1/99)-(1/2+1/4+1/6+...+1/100)=1/51+1/52+1/53+...+1/100
Chứng minh: 1- 1\2 + 1\3 - 1\4 + 1 \5 - 1\6 + ....... + 1\99 -1\100 = 1\51 + 1\52 + 1\53 + ..........+1\100
Chứng minh 1*3*5*...*99=51/2*52/2*53/2*...*100/2
[1+1/3+1/5+....+1/99]-[1/2+1/4+1/6+...+1/100] = 1/51+1/52+1/53+....+1/100
Chứng tỏ A = 1/51 + 1/52 + 1/53 + .....+1/99 + 1/100 <1/2
Bài 19 : Chứng minh rằng :
B = 1/51 + 1/52 + 1/53 +.......+ 1/99 + 1/100 >1/2
Chứng minh rằng: 1 . 3 . 5 . 7 .....99 = 51/2 . 52/2 . 53/2 . 54/2 ......100/2
Chứng minh rằng :
a,1- 1/2 + 1/3 - 1/4 + 1/5 - 1/6 + ...... + 1/ 99 - 1/ 100 = 1 / 51 + 1/ 52 + 1/ 53 + ... + 1/ 100
b, A= 1/3 - 2/ 32 + 3/ 33 - 4/ 34 + .... + 99/ 399 - 100/ 3100 < 3/ 16
Chứng minh 1/51+1/52+1/53+...+1/100>1/2
