Which of the following sets is equivalent to \((P \cup Q) \cap (P \cup Q')\)?

Simplify: \(\frac{\cos 2\theta - 1}{\sin 2\theta}\)

Solve the inequality \(x^{2} - 2x \geq 3\)

Given that \(\sqrt{6}, 3\sqrt{2}, 3\sqrt{6}, 9\sqrt{2},...\) are the first four terms of an exponential sequence (G.P), find in its simplest form the 8th term. 

Given that \(\sin x = \frac{-\sqrt{3}}{2}\) and \(\cos x > 0\), find x.