The average temperature around the tropic of cancer for a particular day in january can be modeled using the equation above, where ttt is the temperature in degrees celsius and ddd is the number of days after january 111 (on january 1, d=01,d=01, comma, d, equals, 0). according to this model, what is the lowest average temperature, in degrees celsius, for a day in january, which has 313131 days?