$($d$)(1$ point$)$ what are the values of the time constant $,$ damping coefficient $,$ and

gain $K$ for the bioreactor?

$($e$)(1$ point$)$ upon a step input in the substrate concentration in the feed $x_f(t),$ do

you expect $b(t)$ to increase or decrease after a long time? do you expect to see

oscillations in $b(t)?$