小学五年级 数学 简便计算!!~~超急啊!!~~急噢噢噢噢哦 请详细解答,谢谢! (19 20:37:56)

来源:百度知道 编辑:UC知道 时间:2024/06/14 19:44:50
1/2+1/4+1/8+1/16+1/32...........+1/1024                 
 
快点啊!!谢谢啊!!
 

1/2+1/4+1/8+1/16+1/32+1/64+.....+1/1024
=1/2+1/4+1/8+1/16+1/32+1/64+.....+1/1024 +1/1024-1/1024
=1/2+1/4+1/8+1/16+1/32+1/64+.....+1/512-1/1024
........
=1-1/1024
=1023/1024

=(1-1/2)+(1/2-1/4)+(1/4-1/8)+.....+(1/512-1/1024)
=1-1/1024
=1023/1024
Ha!Ha!OK!了!
一定要选我。。

1-1/2+1/2-1/4......+1/512-1/1024=1-1/1024=1023/1024

比值为1/2的等比数列,即1/2^1+1/2^2+……+1/2^10,n=10
Sn=a1(1-q^n)/(1-q) ={1/2*[1-(1/2)^10]}/(1-1/2)=1023/1024

或1/2+1/4=3/4,1/2+1/4+1/8=7/8,1/2+1/4+1/8+1/16=15/16,……
1/2+1/4+1/8+1/16+1/32...........+1/1024=1023/1024

原式=(1/2)^1+(1/2)^2+(1/2)^3+......(1/2)^10
a=1/2 q=1/2
由s=a(1—q^10)/(1-q) 得,
原式=1023/1024

1/2+1/4+1/8+1/16+1/32+1/64+.....+1/1024
=1/2+1/4+1/8+1/16+1/32+1/64+.....+1/2^10
=(1/2)(1-(1/2)^10)/(1/2)=1023/1024