SAT

What is your comfort level for SAT questions from 1 (not comfortable at all) to 10 (comfortable)?

What is cos of 150 degrees

[math]\frac{-1}{2}[/math] [math]\frac{\sqrt{3}}{2}[/math] [math]\frac{1}{2}[/math] [math]\frac{-\sqrt{3}}{2}[/math]

Information: SAT