设虚数ci 有2个平方根,有3个立方根ci=ce^[i(2n+1/2)π]√(ci)=(√c)e^[i(n+1/4)π]n=2m,√(ci)=[√(c/2)](1+i)n=2m+1,√(ci)=-[√(c/2)](1+i)(ci)^(1/3)=[c^(1/3)]e^[i(2n/3)π+i(1/6)π]n=3m,(ci)^(1/3)=[c^(1/3)](...