For the graph of a circular function y = f(x), determine whether f(-x) = f(x) or f(-x) = -f(x) is true.
-cos 22° = cos 49°cos 27° - sin 49°sin 27°

Question

Quizplus · Accepted Answer

The correct identity is cos(22°) = cos(49°)cos(27°) + sin(49°)sin(27°), which is derived from the cosine of a difference formula, cos(A - B) = cos(A)cos(B) + sin(A)sin(B), not a subtraction as stated.

For the Graph of a Circular Function Y = F(x)