thing

this is equal to sin (-30) =   - 1/2  

\(Sin(330)\)

\(=\cos \left(90^{\circ \:}-330^{\circ \:}\right)\)

\(=\cos \left(-240^{\circ \:}\right)\)

\(=\cos \left(240^{\circ \:}\right)\)

\(=-\frac{1}{2}\)