Replace a variable in differential equation with 0

I want to reduce this equation by having beta = 0. so that the terms having beta get removed.

((Lemda-((SigmaT(t)).*T))-BetaV(t).*T(t))

[SALAH ALRABEEI]

Can you show your code!

Answer 1

[Walter Roberson]

syms T(t) SigmaT(t) BetaV(t) Lemda To
ode = diff(T,t) == ((Lemda-((SigmaT(t)).*T))-BetaV(t).*T(t))

ode(t) = 

cond = T(0) == To;
zerofun(t) = sym(0)

zerofun(t) = 

0

modified_ode = subs(ode, BetaV, zerofun)

modified_ode(t) = 

Solution = dsolve(modified_ode, cond)

Solution = 

[Fahad Ramzan]

Are these answers the same? Because the solution goes this way where i made assumptions as following

%Assumptions

% Lemda = constant input source of uninfected cells per day

% Sigma = normal loss rate constant of uninfected cells

% Beta = infection rate constant of uninfected cells per infected cell

% Mu = loss rate constant of infected cells

% Gamma = loss rate constant of free virus

% N = number of virions produced per day per infected cell

[Walter Roberson]

Sorry, I am having difficulty reading the image in places, and some of the pieces I think maybe I can read, do not make sense mathematically.