Answer:
y = -3
Explanation:
The midline of a sinusoidal function is the horizontal center line about which the function oscillates periodically.
The midline is positioned halfway between the maximum (peaks) and minimum (troughs) values of the graph. It serves as a baseline that helps visualize the oscillations of the function.
To find the equation of the midline, we need to determine the average y-value between the maximum and minimum y-values.
In this case, the maximum y-value is -1, and the minimum y-value is -5. To find the equation of the midline, sum the maximum and minimum y-values, and divide by 2:

Therefore, the equation of the midline for the graphed sinusoidal function is y = -3.