Check the answer below, please.
1) Before plotting this, we need to remind ourselves the definition of Midline. Roughly saying midline is located halfway between the maximum and the minimum point in a sinusoidal graph.
2) So, bearing in mind the given function we can plot the following:
Note that the dashed line is the midline of that cosine function that is horizontally translated to the left pi/2 units.
Note that the midline marks halfway the maximum and the minimum point.
Thus this is the graph of the function
