(i) Solve the equation \(4 \sin^2 x + 8 \cos x - 7 = 0\) for \(0^\circ \leq x \leq 360^\circ\).

(ii) Hence find the solution of the equation \(4 \sin^2 \left(\frac{1}{2} \theta\right) + 8 \cos \left(\frac{1}{2} \theta\right) - 7 = 0\) for \(0^\circ \leq \theta \leq 360^\circ\).