Final answer:
The cosine of 225 degrees in fraction form is -√2/2.
Step-by-step explanation:
cos 225 degrees fraction form
Solution:
Using the unit circle, we can find the cosine of 225 degrees by looking at the coordinates of the point on the unit circle corresponding to this angle. The point lies in the third quadrant, so the x-coordinate is negative and the y-coordinate is positive. The coordinates are approximately (-√2/2, √2/2).
Since cosine is equal to the x-coordinate of a point on the unit circle, the cosine of 225 degrees can be written as -√2/2.