Answer:
the midline is the line:
y = 0.
Explanation:
The midline of a function is a horizontal line that divides evenly the graph of the function in two parts.
Particularly, for trigonometric functions, we usually have:
f(x) = A*sin(k*x + p) + M
Where:
A is the amplitude.
x is the variable
k is a constant related to the frequency of the function.
p is a phase shift
M is the midline of the function, which means that the line that divides evenly the graph is y = M.
For our case, we have:
y = f(x) = 3*sin(2*x - π)
Then:
A = 3
k = 2
p = -π
And we do not have a constant term in that equation, this means that:
M = 0
This means that the line that divides evenly the graph is the line y = 0.