Additional processes due to biotic and abiotic degradation contributing to souce decay can be accounted for by adding a decay term in (3) that is proportional to m(t),

, (4)

where λ is the associated decay rate constant. Assume that α(

0) and λ(

0) are greater than or equal to zero, then choose one pairs of the vaules of α and λ by yourself and find solutions of Equation (4) using the initial condition m(0)=m0 for the following cases: (i) γ=1, (ii) γ=2, (iii) γ= 0.5. Then , graph the solution for m(t) for each γ

(3)