Prove that \( \begin{array}{ll}\text { (1) } \sin 4 x=4 \sin x \cos x-8 \sin ^{3} x \cos x & \text { (2) } \cos 4 x=8 \cos ^{4} x-8 \cos ^{2} x+1\end{array} \)

In \( \triangle \mathrm{GHI}, g=9.6 \) inches, \( m \angle \mathrm{I}=80^{\circ} \) and \( m \angle \mathrm{G}=15^{\circ} \). Find the length of \( h \), to the nearest 10th of an inch.

In \( \triangle \mathrm{GHI}, g=9.6 \) inches, \( m \angle \mathrm{I}=80^{\circ} \) and \( m \angle \mathrm{G}=15^{\circ} \). Find the length of \( h \), to the nearest 10th of an inch.

In \( \triangle \mathrm{FGH}, f=7.4 \) inches, \( g=1 \) inches and \( h=7 \) inches. Find the measure of \( \angle \mathrm{G} \) to the nearest degree.

In \( \triangle \mathrm{IJK}, k=1.9 \) inches, \( m \angle \mathrm{~J}=59^{\circ} \) and \( m \angle \mathrm{~K}=18^{\circ} \). Find the length of \( j \), to the nearest 10 th of an inch.

(c) \( \sin (\pi+x)+\cos \left(\frac{\pi}{2}-x\right)+\tan \left(\frac{\pi}{2}+x\right)+\tan \left(\frac{3 \pi}{2}-x\right) \)