(a+b)^3=a^3+3a^2*b+3b^2*a+b^3
z^3=(-1/2+√3/2i)^3=-1/8+3√3/8 i +9/8 -3√3/8 i =-1/8+9/8=1
也可以这么算:
z^3=(-1/2+√3/2i)^3=(-1/2+√3/2i)^2*(-1/2+√3/2i)
=(-1/2-√3/2i)*(-1/2+√3/2i)=1/4-(-3/4)=1
(a+b)^3=a^3+3a^2*b+3b^2*a+b^3
z^3=(-1/2+√3/2i)^3=-1/8+3√3/8 i +9/8 -3√3/8 i =-1/8+9/8=1
也可以这么算:
z^3=(-1/2+√3/2i)^3=(-1/2+√3/2i)^2*(-1/2+√3/2i)
=(-1/2-√3/2i)*(-1/2+√3/2i)=1/4-(-3/4)=1