9. In a room, the relationship between temperature in degrees Celsius (I) and time in hours (f) can be represented by a sinusoidal function with once cycle every 24 hours. The temperature has a range of 159 5 7 5 27", with the maximum temperature occurring at 4 pm. (Let f - 0 occur at midnight.) a) State an equation to represent this function: b) Sketch a graph of the function showing at least one period. Label the axes and the S important points. c) From your graph, during one 24-hour period, estimate the length of time (hours) that temperature is greater than 239 C