Question

For the function given, state the middle line: ƒ(t) = 3 cos(π t − 1).

Answer 1

The amplitude is 3 since y = A cos (B ) + C
The vertical shift is C = 0 and B = π t - 1 ( horizontal frequency and shift )
This means that the graph oscillate between -3 and 3.
The middle line is y = 0.