For a particular angle Θ, the cosine function f(x) = a cos b(Θ) has the following values within one cycle of the function:

Question

f(0) = 4; f(pi/4) = 0; f(pi/2) = -4; f(3pi/4) = 0; f(pi) = 4

What is the rule for the cosine function?
A. y = 2 cos 4θ
B. y = 4 cos 2θ
C. y = –4 cos 3θ
D. y = one-fourth cos 2θ

Answer 1

B. y = 4 cos 2θ