x=(1/6)(x+1)^3

问题描述:

x=(1/6)(x+1)^3

x^3+3x^2+3x+1=6x
x^3+3x^2-3x+1=0
2x^3-(x^3-3x^2+3^x-1)=0
2x^3=(x-1)^3
两边开三次方
x=1/(1-2^(1/3))