Question

prove that cos(-x)=-cos x​

Answer 1

Answer:

It shows that the two points have coordinates (x,y) and (x,-y). Since the cosine is the x-coordinate of the points on the unit circle, you see that the two points have the same cosine, and opposite sine. The cosine is an even function, which means exactly that cos(-x) = cos x.

Answer 2

Step-by-step explanation:

Its show that the two points of coordinates (x,y) and (x,y)