1. ## complex numbers

does anyone know if my labels are right. i dont understand the two points re(z3)=0 and im(z4)=0

2. ## Re: complex numbers

swap $z_3$ and $z_4$

On the complex plane, (x,y) = (real, imaginary)

3. ## Re: complex numbers

Let's see.

$Im(z_1)>0$ applies to all but the point on the x axis

$z_2 = 10z_1$ means that $|z_2| = 10|z_1|$

$Re(z_3) = 0$ means $z_3$ lies on the imaginary axis. This is the point you've labeled $z_4$

$Im(z_4) = 0$ means $z_4$ lies on the real axis. This is the point you've labeled $z_3$

So we've got $z_3,~z_4$ figured out.

$z_1,~z_2$ must be as you've labeled them.

So swap, $z_3, ~z_4$ and you're good.