# Midline of sinusoidal functions from graph

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### Problem

Below is the graph of a trigonometric function. It has a maximum point at left parenthesis, minus, start fraction, 5, pi, divided by, 4, end fraction, comma, 6, point, 7, right parenthesis and an amplitude of 4, point, 1.
What is the midline equation of the function?
y, equals