1-1/2+1/4-1/8+1/16-1/32+1/64-1/128+1/256求过程详解,关于错位相减法!

1-1/2+1/4-1/8+1/16-1/32+1/64-1/128+1/256求过程详解,关于错位相减法!
1-1/2+1/4-1/8+1/16-1/32+1/64-1/128+1/256求过程详解,关于错位相减法!

1-1/2+1/4-1/8+1/16-1/32+1/64-1/128+1/256求过程详解,关于错位相减法!
设：S = 1-1/2+1/4-1/8+1/16-1/32+1/64-1/128+1/256
则：（-1/2）S = -1/2+1/4-1/8+1/16-1/32+1/64-1/128+1/256-1/512
两式相减,有：【1-（-1/2）】S=1-（-1/512）
即：（3/2）S=513/512
则：S=171/256

属于分组求和,正项与负项两组，再用公式计算