(1) e^(2z)＝１＋√３i、z=(1/2)*log(1+√3i)=(1/2){log(2)+πi(6n+1)/3}　(nは整数)
(2) tan(z)=i、z=arctan(i)=(1/2)*i*ln{(i+i)/(i-i)}、解無し。