(1) z=a+bi |z|=√(a²+b²)
3a+3bi+√(a²+b²)=3i
3b=3
3a+√(a²+b²)=0
解得b=1 a=-√2/4
z=-√2/4+i
(2) m²+4m+5=(m+2)²+1>0
-m²+2m-2=-(m-1)²-1
(1) z=a+bi |z|=√(a²+b²)
3a+3bi+√(a²+b²)=3i
3b=3
3a+√(a²+b²)=0
解得b=1 a=-√2/4
z=-√2/4+i
(2) m²+4m+5=(m+2)²+1>0
-m²+2m-2=-(m-1)²-1