Question 1122825
{{{ sin( 210 ) = sin( 180 + 30 ) }}}
Rotating the unit vector from 0 degrees in the
Positive direction to {{{ 210 }}} degrees puts it
{{{ 30 }}} degrees past {{{ 180 }}}
which is in the 3rd quadrant.
In the 3rd quadrant, the sin is negative, so
{{{ sin( 210 ) = -sin( 30 ) }}}
{{{ sin( 210 ) = -1/2 }}}