## anonymous 4 years ago find the exact value of sin(pi/12) , cos(pi/12) , and tan(pi/12) using half angle formula.

Well, $\cos(2x) = 2\cos^2 x - 1$ and you know the value of $$\cos(\pi/6)$$ (right? I hope you do). Hence you can find $\cos(\pi/12)$ From that you can find $\sin(\pi/12)$ and tan.