Answer:
[tex]\cos (-270\degree)=0[/tex].
Step-by-step explanation:
We want to find the value of [tex]\cos (-270\degree)[/tex].
Note that;
[tex]\cos (-\theta)=\cos (\theta)[/tex]
This implies that;
[tex]\cos (-270\degree)=\cos (270 \degree)[/tex]
Also 270 degrees is a quadrantal angle.
On the unit circle, [tex]\cos (270\degree)[/tex] is the x-coordinate of the point [tex](0,-1)[/tex]
Hence, [tex]\cos (-270\degree)=0[/tex].
