How to solve a single nonlinear equation with parameter variations?

#Function file

function f=reso(A,w)
global taue k  gamma  hac;
f=(((taue+k.^2)-w.^2)*A+(9/2)*A.^3-(75/64)*A.^5).^2+(gamma*k*w*A).^2-hac.^2;
end

Script file

global taue k  gamma hac;
taue=0.95;
L=5;
k=pi/(2*L);
hac=1.46;
gamma=0.95;
A0=0.001;    %Initial guess
w=0:0.1:5;
for k= 1:length(w)
sol = fzero(@(A) reso(A,w(k)),A0);
plot(w,sol);
end

Here the for loop is not working. Could anybody please point out the problem. Thanks in advance

Answer 1

[VBBV]

 
taue=0.95;
L=5;
kk=pi/(2*L); % change this to different variable 
hac=1.46;
gamma=0.95;
A0=0.01;    %Initial guess
w=0:0.1:5;
for k= 1:length(w)
sol = fzero(@(A) reso(A,w(k),gamma,taue,kk,hac),A0);
plot(w,sol,'bo');
hold on
end

function f=reso(A,w,gamma,taue,kk,hac)
f=(((taue+kk.^2)-w.^2)*A+(9/2)*A.^3-(75/64)*A.^5).^2+(gamma*kk*w*A).^2-hac.^2;
end

Alternately you can pass the variables as arguments in the function call.

You also seem to use the variable k both for parametric values and loop iterator, it essentially overides the value assigned to variables.

Answer 2

[KSSV]

It is suggested not to use global.

Replace these lines:

w=0:0.1:5;
for k= 1:length(w)
sol = fzero(@(A) reso(A,w(k)),A0);
plot(w,sol);
end

with

w=0:0.1:5;
sol = zeros(size(w)) ;
for k= 1:length(w)
    sol(k) = fzero(@(A) reso(A,w(k)),A0);    
end
plot(w,sol)