Below is the graph of a trigonometric function. It has a minimum point at $(1,1.5)$ and an amplitude of 1.5. What is the midline equation of the function?

Please directly answer the question and provide the final value, e.g., 1, 2.5, 300.
Question: Below is the graph of a trigonometric function. It has a minimum point at $(1,1.5)$ and an amplitude of 1.5. What is the midline equation of the function?

Please first conduct reasoning, and then answer the question and provide the final value, e.g., 1, 2.5, 300, at the end.
Question: Below is the graph of a trigonometric function. It has a minimum point at $(1,1.5)$ and an amplitude of 1.5. What is the midline equation of the function?
