Answer and Explanation :
To find : What is the phase shift of a periodic function?
Solution :
The Phase shift is defined as a horizontal shift in a function in any direction.
Horizontal stretches will change the period of the function and that horizontal shift is called a phase shift or the amount of shift in a wave horizontally.
The phase shift is measured in degrees.
Refer the attached figure below for the pictorial representation of teh phase shift.
In the figure, [tex]\frac{\pi }{2} \text{ to } \pi[/tex] is showing the phase shift.
Example - Taking a general example of sin function
[tex]y = A \sin(B(x + C)) + D[/tex]
In this the phase shift is at C (positive is to the left).
