14) The temperature of a 172-degree Fahrenheit covered mug of hot coffee left in a room whose temperature is 68 degrees Fahrenheit can be modeled by the function C(t)=68+104e^-0.65t where t is in hours and C(t) is in degrees Fahrenheit. Find C(0.4) and include the units in your answer. 15) Find the instantaneous rate of change of f(x)=225x2 at x= 9. 16) For f(x)= -11x^2+144x^-2, find the slope of the secant line from x= 6 to x= 2.