chứng minh 1/2<1/51+1/52+1/53+.......+1/99+1/100<1
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
A = 1 . 2 + 2 . 3 + 3 . 4 + ......... + 98 . 99 / 1 + ( 1 + 2 ) + ( 1 + 2 + 3 ) + ........... + ( 1 + 2 + 3 + ...... + 98 )
B = ( 1 / 51 . 52 ) + 1 / 52 . 53 + ...... + 1 / 100 . 101 ) : ( 1 / 1 . 2 + 1 / 2 . 3 + ........ + 1 / 99 . 100 + 1 / 100 . 101
Chứng tỏ rằng tổng của các phân sau lớn hơn 1/2
s=1/50+1/51+1/52+...+1/98+1/99
Chứng minh 1*3*5*...*99=51/2*52/2*53/2*...*100/2
1/51+1/52+1/53+......+1/99+1/100 >1/2
[1+1/3+1/5+....+1/99]-[1/2+1/4+1/6+...+1/100] = 1/51+1/52+1/53+....+1/100
(1/51+1/52+1/53+...+1/100)÷(1/1×2+1/3×4+1/4×5+...+1/99×100)