قانون ديموافر

$find[r(cos\theta +i.sin\theta )]^{\frac{m}{n}}{\color{Red} (m,n\in N)}\\let[r{cos\theta +i.sin\theta }]^{\frac{m}{n}}=t(cos\alpha +i.sin\alpha )\Rightarrow \\r^{m}(cos\theta +i.sin\theta )^{m}=t^{n}(cos\alpha +i.sin\alpha )^{n}\Rightarrow \\r^{m}(cos(m\theta+2k\pi )+i.sin(m\theta +2k\pi ))=t^{n}(cos(n\alpha )+i.sin(n\alpha )){\color{Red} (k=0,1,2,..n-1)}\\\Rightarrow (1)t=r^{\frac{m}{n}}(2)\alpha _{k+1}=\frac{m\theta +2k\pi }{n}$