Answer:
y = 1
Explanation:
This is very simple.
The mid-line of a sinusoidal function is the horizontal line that passes through the middle of the extreme values.
The midline of a sinusoid of the form y = a Cos (bx + c) + d is going to be
y = d
The form y = a Cos (bx + c) + d is the transformed of the version y = Cos x. Midline is only affected by a vertical shift, which is d.
Thus, the midline of the equation given y=2 cos (4∅+5) + 1 is y = 1