e^(x+yi)=e^x e^(yi) = (2+2^0.5 i) = 6^0.5 e^(i atan(2^0.5 / 2))
x = 0.5 ln(6)
y = atan(2^0.5 / 2) + 2kπ,k为整数答案是z=1/2ln6+i(2kpai+arctan√2/2)一样的.