$\cos 48^{\circ} \cdot \cos 12^{\circ}=$

Question

Aicharya · Accepted Answer

$\begin{aligned} & \cos 48^{\circ} \cdot \cos 12^{\circ}=\frac{1}{2}\left(2 \cos 48^{\circ} \cdot \cos 12^{\circ}\right) \ &=\frac{1}{2}\left[\cos 60^{\circ}+\cos 36^{\circ}\right]=\frac{1}{2}\left[\frac{1}{2}+\frac{\sqrt{5}+1}{4}\right] \ &=\left(\frac{3+\sqrt{5}}{8}\right) \end{aligned}$

\(\cos 48^{\circ} \cdot \cos 12^{\circ}=\)

Solution