=>S<1/1.2+1/2.3+1/3.4+...+1/98.99+1/99.100=1-1/2+1/2-1/3+1/3-1/4+...+1/99-1/100
=1-(1/2-1/2)-(1/3-1/3)-...-(1/99-1/99)-1/100
=1-1/100 <1
=>S<1
Vậy S<1
1/1.3-1/2.4+1/3.5-1/4.6+...+1/97.99-1/98.100 = ?
1/1.3+1/2.4+1/3.5+....+1/97.99+1/98.100 <3/4
chứng minh rằng:1/1.3 + 1/2.4 + 1/3.5 + 1/4.6 +....+ 1/97.99 + 1/98.100 < 3/4
chứng minh rằng 1^1.3 + 1^2.4 + 1^3.5 + 1^4.6 +...+ 1^97.99+ 1^98.100 < 3^4
Tính
\(S=1.3+2.4+3.5+4.6+....+97.99+98.100..\)
Chứng minh rằng: \(\frac{1}{1.3}+\frac{1}{2.4}+\frac{1}{3.5}+\frac{1}{4.6}+...+\frac{1}{97.99}+\frac{1}{98.100}< \frac{3}{4}\)
1.3+2.4+3.5+...+97.99+98.100
1.3+2.4+3.5+...+97.99+98.100
1/3.4+1/2.4+1/3.5+....+1/97.99+1/98.100<3/4