tinh a=1/2+1/4+1/8+1/16+.....(tong co 10so hang)
a=...(viet phan so toi gian)
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
1/4+1/8+1/16+...
=1/4+1/8+1/16+1/32+1/64+1/128+1/256+1/512+1/1024+1/2048
=1/2-1/4+1/4-1/8+1/8-1/16+1/16-1/32+1/32-1/64+1/64-1/128+1/128-1/256+1/256-1/512+1/512-1/1024+1/1024-1/2048
=1/2-1/2048
=1024/2048-1/2048
=1023/2048
a) đây chỉ là 1 trong nhiều cách
\(\frac{7}{8}=\frac{1}{8}+\frac{4}{8}+\frac{2}{8}\)
a) \(\frac{7}{8}=\frac{1}{2}+\frac{1}{4}+\frac{1}{8}\)
b) \(\left(1-\frac{1}{2}\right).\left(1-\frac{1}{3}\right).\left(1-\frac{1}{4}\right).\left(1-\frac{1}{5}\right)\)
\(=\frac{1}{2}.\frac{2}{3}.\frac{3}{4}.\frac{4}{5}\)
\(=\frac{1.2.3.4.}{2.3.4.5}\)
\(=\frac{1}{5}\)
( Dấu chấm là dấu nhân nha bạn )
tong tren co 10 so hang suy ra ps cuoi cung la 1/2014
Suy ra tong=1023/1024
2A=\(2x\left(\frac{1}{2}+\frac{1}{4}+\frac{1}{8}+\frac{1}{16}+\frac{1}{32}+\frac{1}{64}+\frac{1}{128}+\frac{1}{256}+\frac{1}{512}+\frac{1}{1024}\right)\)
2A=\(1+\frac{1}{2}+\frac{1}{4}+\frac{1}{8}+\frac{1}{16}+\frac{1}{32}+\frac{1}{64}+\frac{1}{128}+\frac{1}{256}+\frac{1}{512}\)
2A-A=\(1-\frac{1}{1024}\)
A=\(\frac{1023}{1024}\)
a = 1/2+1/4+1/8+1/16
= (1 - 1/2) + (1/2 -1/4) + (1/4 - 1/8) + ... + (1/512 - 1/1024).
= 1 - 1/1024
= 1023/1024
A=1/2+1/4+1/8+1/16
A=1/2+(1/2-1/4)+(1/4-1/8)+(1/8-1/16)+....+(1/512-1/1024)
=1/2+1/2-1/1024
=1-1/1024=1023/1024
DS : 1023/1024
2a=\(1+\frac{1}{2}+\frac{1}{4}+\frac{1}{8}+\frac{1}{16}+\frac{1}{32}+\frac{1}{64}+\frac{1}{128}+\frac{1}{256}+\frac{1}{512}\)
2a-a=\(1-\frac{1}{1024}\)
a=\(1-\frac{1}{1024}\)
a=\(\frac{1023}{1024}\)
a= 1023/1024
**** mik nha bn !!!