Function y=cosx
For the given function:
Phase shift: how fat the function is shifted horizontally from the ussual position: In y=cosx the first wave goes to minimum in π and in the given graph in π/2.
Phase shifth:
Midline: In y=cosx the midline is y=0.
In the given graph the midline is in y=1
Period: Measure from one peak to next.
Period: π