Which statement regarding the function y=cos(x) is true? a. cos(x) = cos(-x) b. since the cosine function is even, reflection over the x-axis does not change the graph. c. cos(x) = -cos(x) d. the cosine function is odd, so it is symmetrical across the origin.

A. cos(x) = cos(-x)  [correct, since cos(x) is an even function]
B. Since the cosine function is even, reflection over the x-axis [y-axis] does not change the graph.  [false]
C. cos(x) = -cos(x)   [ false]
D. The cosine function is odd [even], so it is symmetrical across the origin.   [false]