The daily low temperature in Guangzhou, China, varies over time in a periodic way that can be modeled by a trigonometric function. The period of change is exactly 111 year. The temperature peaks around July 262626 at 78^\circ F78 ∘ F78, degrees, F, and has its minimum half a year later at 49^\circ F49 ∘ F49, degrees, F. Assuming a year is exactly 365365365 days, July 262626 is \dfrac{206}{365} 365 206 start fraction, 206, divided by, 365, end fraction of a year after January 111. Find the formula of the trigonometric function that models the daily low temperature TTT in Guangzhou ttt years after January 111, 201520152015. Define the function using radians.