7 The complex number \(u\) is given by \(u = \frac { 7 + 4 \mathrm { i } } { 3 - 2 \mathrm { i } }\).
- Express \(u\) in the form \(x + \mathrm { i } y\), where \(x\) and \(y\) are real.
- Sketch an Argand diagram showing the point representing the complex number \(u\). Show on the same diagram the locus of the complex number \(z\) such that \(| z - u | = 2\).
- Find the greatest value of \(\arg z\) for points on this locus.