tanz=sinz/cosz=(e^iz-e^-iz)/[i(e^iz+e^-iz)]=(t-1/t)/[i(t+1/t)]=(t^2-1)/[i(t^2+1)], 这里t=e^iz 方程化为:(t^2-1)=i(t^2+1)(1+2i) 化为: t^2-1=(t^2+1)(i-2) t^2=(-2+i)/5, 令z=a+bi e^2i(a+bi)=(-2+i)/5=1/√5 e^iu, u=π-arctan(1/2) e^(2.
如下: