Why is my iteration not working. ? ( the solution array has all the same value from first iteration )

     %function F = Gaddis(x)

for (i = 1:40)
    vol(1) = 5*10^(-6);  % volumetric gas flow rate 

sig = 0.0728;     
do = 6*(10^(-3));  
den = 998;          
g = 9.81;
mu = 8.9*10^(-4);     
s = (6*do*sig/(den*g));
L = (81*mu*vol(i)/(pi*g*den));
T = (135*(vol(i)^2)/(4*(pi^2)*g));
F = (x^3) - s - (L/x) - (T/(x^2));
vol(i+1) = vol(i) + 10^(-6);  

end
end
I used fsolve solver to solve this function . '
As my volume changes , i am supposed to get new values of diametre , but it shows the same value for all the 40 iterations.

command code xsol(i) = fsolve(@(x) Gaddis(x), 0.0001);

Answer 1

[Torsten]

function main  
for i=1:40
  vol(i) = 5e-6+(i-1)*1e-6;
  xsol(i)=fsolve(@(x)Gaddis(x,vol(i)),1e-4);
end
plot(vol,xsol)

function F = Gaddis(x,vol)
sig = 0.0728;     
do = 6*(10^(-3));  
den = 998;          
g = 9.81;
mu = 8.9*10^(-4);     
s = (6*do*sig/(den*g));
L = (81*mu*vol/(pi*g*den));
T = (135*(vol^2)/(4*(pi^2)*g));
F = (x^3) - s - (L/x) - (T/(x^2));

Best wishes

Torsten.

[Jaunty Jose]

But it does show error, undefined variable 'x' on running it