1
Q
z is completely real
A
y=0
2
Q
z is completely imaginary
A
x=0
3
Q
z1z2=
A
(x1x2-y1y2)+i(x1y2+x2y1)
4
Q
reciprocal of z
A
1/z=z(conjugate)//|z|^2
5
Q
the argument of z is
A
@=tan-1(y/x)
6
Q
principal value of argument
A
@, π-@, - π+@, -@
7
Q
polar form
A
z=r(cos@+isin@) where r=|z| and @=arg(z)
8
Q
eulers form
A
z=re^i@, r=|z| @=arg(z)
9
Q
cube root of unity
A
are 1,w,w^2
10
Q
value of w
A
w=-1+√3 i/2 w^2=-1-√3 i/2
11
Q
properties of cube root
A
1+w+w^2=0
w^3=1
