Il scriem pe π/12 ca diferenta dintre π/3 si π/4 si vom folosi formula sinusului de diferenta:
[tex]sin( \frac{\pi}{12} )=sin( \frac{\pi}{3}- \frac{\pi}{4} )=sin \frac{\pi}{3} cos \frac{\pi}{4} -cos \frac{\pi}{3} sin \frac{\pi}{4}=\\
= \frac{ \sqrt{3} }{2} * \frac{ \sqrt{2} }{2} - \frac{ \sqrt{2} }{2} * \frac{1}{2} = \frac{ \sqrt{6} }{4} - \frac{ \sqrt{2} }{4} = \frac{ \sqrt{6} - \sqrt{2} }{4} [/tex]
