Chứng minh rằng:
a) A= 1/ 2.2 + 1/3.3 + 1/4.4 +....+ 1/100.100 < 1
1/2.2+1/3.3+1/4.4+....+1/100.100<1
A=1+2.2!+3.3!+4.4!+...+100.100!
tinh : A = (1 - 1/2.2) . (1 - 1/3.3) . (1 - 1/4.4)...(1 -1/100.100)
CMR: 1/2.2 +1/3.3+1/4.4+....+1/100.100<1
Mik cần gấp
1/3.3+1/4.4+1/5.5...+1/100.100<1/2 ( chứng minh)
A =1.1+ 2.2+ 3.3+ 4.4+ ..... +99.99+ 100.100
E= 1.1+2.2+3.3+4.4+......+100.100
Chứng minh A=1/2.2+1/4.4+1/6.6+............+1/100.100<1/2