Question

Locate the points for which 3< |z| < 4

Answer 1

Answer:

These are the points in the open annulus with outer radius 4 and inner radius 3.  In other words, its the region you get by cutting a (closed) disc of radius 3 out of a(n open) disc of radius 4.

Step-by-step explanation:

The requirement that |z| < 4 just says that the magnitude of z is less than 4. These are the points inside the disc of radius 4.

The requirement that 3 < |z| says that the points must have magnitude greater than 3.  So the points of interest are those outside the disc of radius 3.

The points inside the larger disc but outside the smaller disc then form the annulus mentioned.