Question 1 of 20
Time: 00:00
If $z=x+iy$ then |z|=
Difficulty: Hard
A:

$\sqrt{x^{2}+y^{2}}$

B:

$\sqrt{x^{2}-y^{2}}$

C:

$x^{2}+y^{2}$

D:

$x^{2}-y^{2}$