T =ƒ­aƒy+ beƒ{^- kt (Equation 2)

Question

where T is the temperature at time t, and a, b and k are constants with
values a = 20 „aC, b = 80 „aC and k = 2.6 ¡Ñ 10ƒ{4 sƒ{1.
Differentiate Equation 2 with respect to t and thus give values (with
appropriate units and to two significant figures) for the rate of change of
temperature with time at times of 1.0 ¡Ñ 103 s and 5.0 ¡Ñ 103 s.