Question

Which of the following would best represent a cosine function with an amplitude of 3, a period of pi over 2, and a midline at y = −4?

f(x) = −4 cos 4x + 3
f(x) = 3 cos(x − pi over 2) − 4
f(x) = 4 cos(x − pi over 2) + 3
f(x) = 3 cos 4x − 4

Answer 1

f(x) = 3 cos 4x − 4

Explanation:

Answer 2

The second choice is the correct answer I believe. Mid-line is always at the end so the only options you would have is the second choice and the last but you cant have your period equal to zero.