(i)[3]
Show that the expression $\sin(\theta + 60^\circ) + \sin(\theta + 120^\circ)$ is equal to $\sqrt{3} \cos \theta$.
(ii(a))[2]
Find the exact value of the expression $\sin 105^\circ + \sin 165^\circ$.
(ii(b))[3]
Solve the equation $\sin(\theta + 60^\circ) + \sin(\theta + 120^\circ) = \sec \theta$ within $0^\circ \leq \theta \leq 180^\circ$.