Đặt S = 1/2 + 1/4 + 1/8 + 1/16 + ...
==> 2S = 1 + 1/2 + 1/4 + 1/8 + 1/16 + ...
2S = 1 + S
==> S = 1
Ta có 2xA=1+1/2+...+1/512
Do đó: A=2xA-A=1-1/1024=1023/1024.
Tính tổng:1 + 1/2 + 1/4 + 1/8 + 1/16 + ...+ 1/512 + 1/1024
C=3/2+3/4+3/8+3/16+...+3/128
D=1/2+1/4+1/8+...+1/1024
E=5/2+5/8+5/32+5/128+5/512+5/2048
tinh nhah
1/2+1/4+1/8+1/16+1/32+1/64+1/128+1/256+1/512+1/1024 ket qua bang bao nhieu
A=1/2+1/4+1/8+....+1/512+1/1024
tính nhanh tổng sau :
a, D=1/2+1/4+1/8+1/16+1/32+•••+1/512+1/1024
b, Đ=1/1*2+1/2*3+1/3*4+•••+1/18*19+1/19*20
c,E=1/11*16+1/16*21+1/21*26+•••1/56*26+1/61*-6
Ai nhanh thì mình tick
a.\(\frac{1}{2}+\frac{1}{4}+\frac{1}{8}+......+\frac{1}{512}+\frac{1}{1024}\)
b.\(\frac{1}{8}+\frac{1}{48}+\frac{1}{80}+.....+\frac{1}{10200}\)
Tính 1/2-1/4-1/8-1/16-....-1/1024
1+1/2+1/4+1/8+1/16+1/32+......+1/1024
1/2+1/4+1/6+1/8+1/16+...+1/256+1/512 = ?
