6 The complex number \(3 - 3 \mathrm { i }\) is denoted by \(a\).
- Find \(| a |\) and \(\arg a\).
- Sketch on a single Argand diagram the loci given by
(a) \(| z - a | = 3 \sqrt { 2 }\),
(b) \(\quad \arg ( z - a ) = \frac { 1 } { 4 } \pi\). - Indicate, by shading, the region of the Argand diagram for which
$$| z - a | \geqslant 3 \sqrt { 2 } \quad \text { and } \quad 0 \leqslant \arg ( z - a ) \leqslant \frac { 1 } { 4 } \pi$$