Question

Use half angle identities to fine the exact value for sin 5pi/12

Answer 1

$$\bf \large {
\cfrac{5\pi}{12} \times 2 \implies \cfrac{5\pi}{6}\\
\cfrac{\frac{5\pi}{6}}{2} \implies \cfrac{5\pi}{12}\\
sin\left(\cfrac{\frac{5\pi}{6}}{2}\right) = \pm\sqrt{\frac{1-cos\left(\frac{5\pi}{6}\right)}{2}}
}
$$