The unit circle is a circle centered at origin with radius 1. The values of the circle depends on the values of the angle created.
Below, we show the unit circle:
The x coordinate and y coordinate will make up a right triangle that has a hypotenuse of 1.
We can use the Pythagorean Theorem to write it as:
The x is what we want and y is already given. Let's substitute and find the value of x:
This isn't one of the answer choices, so we simplify it further to match one of the answer choices. let's multiply it with Sqrt(3) OVER Sqrt(3).
Thus,
Correct Answer is B