1⼀2+(1⼀2)^2+(1⼀2)^3+(1⼀2)^4+(1⼀2)^5+(1⼀2)^6+(1⼀2)^7+(1⼀2)^8

2024-12-21 01:49:42
推荐回答(1个)
回答1:

  方法一:用公式1/2+(1/2)^2+(1/2)^3+(1/2)^4+(1/2)^5+(1/2)^6+(1/2)^7+(1/2)^8
  =1/2[1-(1/2)^8]/(1-1/2)= 1-(1/2)^8=255/256

  方法二:1/2+(1/2)^2+(1/2)^3+(1/2)^4+(1/2)^5+(1/2)^6+(1/2)^7+(1/2)^8
  =1/2+(1/2)^2+(1/2)^3+(1/2)^4+(1/2)^5+(1/2)^6+(1/2)^7+(1/2)^8+(1/2)^8-(1/2)^8
  =1-(1/2)^8=255/256