1/2+1/4+1/8+1/16+……1/128=?要简便算法
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1/2+1/4+1/8+1/16+……1/128=?
要简便算法
必须根据小学的理解力来解题,高等方法不被接受
1/2+1/4+1/8+1/16+1/32+1/64+1/128
=(1/2+1/4+1/8+1/16+1/32+1/64+1/128+1/128)-1/128
=(1/2+1/4+1/8+1/16+1/32+1/64+1/64)-1/128
=(1/2+1/4+1/8+1/16+1/32+1/32)-1/128
=(1/2+1/4+1/8+1/16+1/16)-1/128
=(1/2+1/4+1/8+1/8)-1/128
=(1/2+1/4+1/4)-1/128
=(1/2+1/2)-1/128
=1-1/128
=127/128
高中时候的等比数列,后边每一项都是前一项乘以1/2得到的。有公式的,前n项和Sn=a1(1-q的n次幂)/(1-q),最后为127/128
=1-1/128=127/128
1/2+1/4+1/8+1/16+1/32+1/64+1/128
=(1/2+1/4+1/8+1/16+1/32+1/64+1/128+1/128)-1/128
=(1/2+1/4+1/8+1/16+1/32+1/64+1/64)-1/128
=(1/2+1/4+1/8+1/16+1/32+1/32)-1/128
=(1/2+1/4+1/8+1/16+1/16)-1/128
=(1/2+1/4+1/8+1/8)-1/128
=(1/2+1/4+1/4)-1/128
=(1/2+1/2)-1/128
=1-1/128
=127/128
分子为64+32+16+8+4+2+1=127,即一百二十八分之一百二十七!
63/64
2/1+4/1+8/1+16/1+32/1……+1024/1=
1/2+1/4+1/8+1/16+……+1/1024+1/2048=?
1/2+1/4+1/8=1/16+1/32+……+1/1024+2048
1/2+1/4+1/8+1/16+……+1/1024+1/2048=?]
1/2+1/4+1/8+1//16+1/32……1//128
1/2+1/4+1/8+1/16+……+1/2n的值
简便计算:1/2+1/4+1/8+1/16+……+1/256
1/2+1/4+1/8+1/16+……1/128=?要简便算法
1/2+1/4+1/8+1/16+……+1/256=( )
2/1+4/1+8/1+16/1+……+256/1=( )
1,1/2,1/4,1/8,1/16……第100个数是
简便计算:1-1/2-1/4-1/8-1/16-1/32-…-1/1024
1/2+1/4+1/8+1/16+1/32+……+1/1024+1/2048+1/2^n
1+2+4+8+16+……+1024等于几?
1+2+4+8+16+……+1024
求和:1/2-1/4+1/8-1/16+……+(-1)^n-1*1/2^n
简算:1/2+1/4+1/8+1/16+1/32+…+1/4096=()
1/2+1/4+1/8……+1/256