Strange to call cooling constant, k, instead of some other variable as it looks like a conductivity. Anyway, I'm not sure how this is answered as a precalculus question unless you know that the form of the F(t) = C1e-kt + C2
In terms of calculus, the solution is found using the differential equation dT/dt = -k(T-T∞) (If T is higher than T∞, the change in temperature will be negative in proportion to the difference). This equation is separable and solvable with the initial condition for T(0)
The solution to this differential equation T = (T0-T∞)e-kt + T∞ which you can see, goes from T0 at t = 0 and T∞ as t → ∞
Please consider a tutor. Take care.
