save the value in side the function file

I have 3 m-files let say:

 function [f]=fun(g)
     Myy=20*x^2; % Assume we know x matrix
     f=Myy;

the 2nd file is

    function [c]=bisect(fun,a,b)
     Ma=fun(a);
     Mb=fun(b)
     c=(a+b)/2;

Third file:

a= 1; b=2; 
c=bisect(@fun,a,b)

If I run the third file, how do I save (store) value of f every time, a,b is changed. Thanks

Answer 1

[Azzi Abdelmalek]

k=0;  
a= 1; 
b=2;
k=k+1 
c{k}=bisect(@fun,a,b)

[Laura]

I tried that but it seems to be not working.

Answer 2

[Azzi Abdelmalek]

k=0;  
a= 1; 
b=2;
k=k+1 
c{k}=bisect(@fun,a,b)