Chemical Engineering - Process Control and Instrumentation - Discussion

Suppose that the gain, time constant and dead time of a process with the following transfer function:G_c(s) = 10 exp( - 0.1s)/(0.5s + 1) are known with a possible error of ± 20% of their values. The largest permissible gain K_c of a proportional controller needs to be calculated below taking the values of process gain, time constant and dead time as