Question

Complex numbers help. Question attached below.

Answer 1

Can I have some help to the second part of this question? I've already expressed z in the form p+qi and ended up with 1+2i. I need help along with an explanation for the Argand diagram bit :S

Answer 2

if i am not mistaken that is saying that the distance between \(z\) and \(1+2i\) is \(\sqrt5\) so it would be a circle

Answer 3

I understand the diagram..but doesn't it mean that it is a circle centered at (1,2i) with a radius √5?