Answer:
[tex]u(t)=T+(u_{0}-T})e^{-kt}[/tex]
Step-by-step explanation:
We know:
[tex]\frac{du}{dt} = -k(u-T)[/tex]
We integrate in order to find u(t):
[tex]\int\limits^u_{u_{0}} {\frac{1}{-k(u-T)} \, du } = \int\limits^t_0 \, dt[/tex]
[tex]ln(\frac{u-T}{u_{0}-T} )=-kt\\[/tex]
[tex]u(t)=T+(u_{0}-T})e^{-kt}[/tex]