tinh -1-1/2(1+2)-1/3(1+2+3)-...-1/101(1+2+3+...+101)
nhanh len nhe hu hu hu
tinh nhanh :A=(1-1/2).(1-1/4).(1-1/90)...(1-1/10000)
B=(1/1*3+1).(1/2*4+1).1/3*5+1)...(1/99*101+1)
tinh nhanh
a) A= 33(1-2/3)(1-2/5)...(1-2/99)
b) B=101+100+99+98+...+3+2+1/101-100+99-98+...+3-2+1
c) C=423134x846267-423133/423133x846267+423134
CMR:
a)\(\frac{1}{2}+\frac{1}{2^2}+\frac{1}{2^3}+...+\frac{1}{2^7}\) <1
b)\(\frac{1}{3}+\frac{2}{3^2}+\frac{3}{3^3}+\frac{4}{4^4}+....+\frac{101}{3^{101}}\),<3/4
nhanh nhé
cho a=1/2+1/3+1/4+...+1/108+1/109 va b= 108/1+107/2+106/3+...+2/101+1/108 tinh a/b
Chứng minh rằng 1/1*2+1/1*2*3+1/1*2*3*4+...+1/1*2*3*4*...*101 < 1
(1/2!+1/3!+1/4!+...+1/101!)
TÍNH:
a)-1-1/2.(1+2)-1/3.(1+2+3)-...-1/101.(1+2+3+...+101)
b) 1/77.7^4.11^2.(77)^4.(1/7^2)^8.(7^8)^3.(-11)^3:(7^15.11^8
c) 1:0.25.(1+1/4)^2+25.[1:(4/3)^2 : (5/4)^3] : [1:(-2/3)^3]
GIÚP MÌNH VỚI
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
1;tinh
a;1-2-3+4+5-6-7+8+....+1993-1994
b;1^2-2^2+3^2-4^2+.....+99^2-100^2+101^2
