a/(x,) k,1(x,1)+k,S(x,1)+DQ21(x,1 at a1(x)k k 2 x +SX steady-state D D 02(x)=a(x)-b-x MATLAB can solve this for you >>dso1ve("D2x=a*x-b-c*t!,"Dx(0)=0,Dx(1)=0") ans (b+C*t)/a+c*(-1+cosh(a^(1/2)))/a^(3/2)/sinh(a^(1/2))*cosh(a~(1/2)*t c/a^(3/2)*sinh(a^(1/2)*t)2 2 ( , ) ( , ) ( , ) ( , ) x I x t k I x t k S x t D t I x t I I ∂ ∂ = − + + ∂ ∂ − [ ] aI x b cx x I x s s x D k I x D k x I x o I I = − − ∂ ∂ = − + ∂ ∂ − ( ) ( ) ( ) ( ) 2 2 2 1 2 steady-state: MATLAB can solve this for you: >> dsolve('D2x=a*x-b-c*t','Dx(0)=0,Dx(1)=0') ans = (b+c*t)/a+c*(-1+cosh(a^(1/2)))/a^(3/2)/sinh(a^(1/2))*cosh(a^(1/2)*t) -c/a^(3/2)*sinh(a^(1/2)*t) 11