Midline
Definition of Midline
- The midline is a horizontal axis that is used as the reference line about which the graph of a periodic function oscillates.
Examples of Midline
- Figure 1 shows y = sin x and Figure 2 shows y = sin x + 1. The second curve is the first curve shifted vertically up by one unit. The midline of y = sin x is the x-axis and the midline of y = sin x + 1 is the line y = 1.
More about Midline
- The equation of the midline of periodic function is the average of the maximum and minimum values of the function.
Solved Example on Midline
Which of the following is the equation of the midline of the curve y = cos x - 3?
Choices:
A. 
B. 
C. 
D. 
Correct Answer: B
Solution:
Step 1: The equation of the midline of periodic function is the average of the maximum and minimum values of the function.
Step 2: The cosine curve varies from – 1 to + 1 . So, the maximum value of the function y = cos x – 3 is – 2 and the minimum value of the function is – 4.
Step 3: Therefore the equation of the midline of the given function is the line
.
Related Terms for Midline
- Horizontal Axis
- Periodic Function
Additional Links for Midline
