# Thread: Sketching in the complex plane

1. ## Sketching in the complex plane

Sketch the following:

$A = \{ z \in C \ | \ |z| = 2 - Re(z) \}$

I have the answer in front of me, but I just dont understand the following:

$x^2 + y^2 = (2-x)^2$

Why did they square the $(2-x)$ part?

2. Originally Posted by janvdl
Sketch the following:

$A = \{ z \in C \ | \ |z| = 2 - Re(z) \}$

I have the answer in front of me, but I just dont understand the following:

$x^2 + y^2 = (2-x)^2$

Why did they square the $(2-x)$ part?
Because $|z| = \sqrt{x^2+y^2}$. So they squared both sides.

3. Originally Posted by Opalg
Because $|z| = \sqrt{x^2+y^2}$. So they squared both sides.
I knew it was something simple that I missed again!

Thanks Opalg.