Answer
$sin(-150°)=-\frac{1}{2}$
$cos(-150°)=-\frac{\sqrt 3}{2}$
$tan(-150°)=\frac{\sqrt 3}{3}$
Work Step by Step
Let $θ'$ be the reference angle. We must have that $0°\leqθ'\lt360°$
$θ'=θ+n·360°$, where $n$ is an integer.
$θ'=-150°+360°=210°$
$sin(-150°)=sin~210°=-\frac{1}{2}$
$cos(-150°)=cos~210°=-\frac{\sqrt 3}{2}$
$tan(-150°)=tan~210°=\frac{\sqrt 3}{3}$
