Answer:
[tex]y=2[/tex]
Step-by-step explanation:
A midline of a cosine function is the horizontal center line about which the function oscillates above and below.
Given the function
[tex]f(x)=2+\cos x[/tex]
The function [tex]y=\cos x[/tex] has the range [tex]y\in [-1,1][/tex] and, therefore a midline with equation [tex]y=0.[/tex]
The graph of the function [tex]f(x)[/tex] can be obtained by translation the graph of the function [tex]y=\cos x[/tex] wo units up. Hence, the midline will be translated 2 units up too and its equation will be
[tex]y=2[/tex]
