The angle -80° is located at the IV quadrant:
In this quadrant, the x-coordinates are positive, which means, cosine is positive, and the y-coordinates are negative, then sine is negative.
Also tangent is:
[tex]\tan \theta=\frac{\sin \theta}{\cos \theta}=\frac{-}{+}[/tex]Thus, by the law of signs, the tangent is negative in the IV quadrant.
Therefore, the answer is:
cos(-80°)>0 and tan(-80°)<0
