# problem with integral

hi my friends.
I have a problem and i want your help.I have the next code.I want to find the integral(0,inf) of final for v=-12:0.05:2.for one value of v,for example
-11.95,the code gives me a result.When i try to change the value of v,-10.95 for example the value of subtotal is again the same and i dont know why.Why this happens?is there a problem in my code?Do you know what can i change to have for each value of v the equivalent subtotal and total?Because i want to make a plot(vdot,total) and with this code i think that the result will be a straight line which is wrong.
A=12.56e-4;
L=0.44;
vdot=v/L
G=2;
T=300;
q=1.6e-19;
k=8.62e-5;
%Edot between 0.01-0.7
Edot=0.01;
%Ndot between 10^8-10^15
Ndot=10^8;
%DE between 0.01-0.5
DE=0.05;
syms E;

denom=1+exp((E-q*vdot)/(k*T));
function1=1./denom;
static=(G*Ndot)/(sqrt(pi/2)*DE);
ek8eths=((E+Edot+q*vdot)/DE).^2;
function2=exp(-2*ek8eths);
function3=function1.*static;
final=function3.*function2;

%or if i try final=function1.*function2.*static is correct?

subtotal=double(int(final,E,0,inf))
total=q*A*L*subtotal

Maybe if i try to solve it with gaussian integral?But i dont know how to use this method...