z=a+bi
z conjugat=a-bi
z²=(a+bi)²=a²+2abi+b²i²=a²-b²+2abi
a-bi=a²-b²+2abi
egalam partile reala si imaginara
-bi=2abi
a=a²-b²
-b=2ab
2ab+b=0
b(2a+1)=0
1.b=0
arunci a=a²
a²-a=0
a=1
a=0
z1=0+0i=0∈R
z2=1+0i=1∈R
2)2a+1=0
a=-1/2
b²=a²-a=(-1/2)²-(-1/2)=1/4+1/2=3/4
b1,2=+-√3/2
z3=-1/2-i√3/2 =omega
z4=-1/2+i√3/2=omega barat
extra
z3 si z4 sunt radacinile cubice complexe ale lui 1
