Formulate a one-dimensional model describing the dynamics of phytoplankton growth C(x, t)
in a water mass taking into account the following: D , its diffusion coefficient, a its rate of
growth, b its mortality rate due to sinking. Fixing the area of interest as 0 <[= x <=1 and the initial
concentration of phytoplankton as 20 moles / cm cube, find the concentration distribution of
phytoplankton in 0 <=x <=1 at any time t .