9709 P33 - Nov 2021 - Q11
1933
\(The complex number -\sqrt{3} + i is denoted by u.\)
\((a) Express u in the form re^{i\theta}, where r > 0 and -\pi < \theta \leq \pi, giving the exact values of r and \theta.\)
(b) Hence show that u^6 is real and state its value.
(c) (i) On a sketch of an Argand diagram, shade the region whose points represent complex numbers z satisfying the inequalities 0 \leq \arg(z - u) \leq \frac{1}{4}\pi and \text{Re } z \leq 2.
(ii) Find the greatest value of |z| for points in the shaded region. Give your answer correct to 3 significant figures.
