Answer:
[tex]y=2[/tex]
Step-by-step explanation:
In [tex]y=a\cos(bx-c)+d[/tex], [tex]d[/tex] represents the vertical shift. The midline of the function is given by [tex]y=d[/tex], because the parent function [tex]y=\cos x[/tex] has a midline at [tex]y=0[/tex]. Therefore, the midline of the function [tex]y=\cos (\frac{2\pi}{3}x)+2[/tex] is [tex]\boxed{y=2}[/tex]
