
3^0+3^1+3^2+3^3+~~~~~+3^100=
解:毕逗令S=3^0+3^1+3^2+3^3+~~~~~+3^100(1)
则3S=(3^0+3^1+3^2+3^3+~~~~~+3^100)*3
=3^1+3^2+3^3+~~~~~+3^100+3^101(2)
(2)-(1)得:2S=3^101-3^0=3^101-1
所山租以S=(3^101-1)/2
即3^0+3^1+3^2+3^3+~~~~~+3^100=(3^101-1)/2
希望采手唯卖纳!!
等比数列求和公式
(1-3^101)/(1-3) * 3^0 = (3^101-1)/2