Answer:
[tex]cos150 = -\frac{\sqrt{3} }{2}[/tex]
Step-by-step explanation:
Recall the unit circle. At 150 deg, the point value is (-sqrt3/2, 1/2)
Remember the cosine is always the x-value, and sine is always the y-value.
This means that cosine will be -sqrt3/2.
