Hi, I am getting error on secant problem.

when I type in command window i get the following

Xs=(exp(-x)-x,0,1,.001,3)
Xs=(exp(-x)-x,0,1,.001,3)
            ↑
Error: Expression or statement is incorrect--possibly unbalanced (, {, or [.
Here is my program

function Xs=secantroot (fun,Xa,Xb,tol,n)
for i=1:n
  funXb=feval(fun,Xb);
  Xi=Xb-funXb*(Xa-Xb)/(feval(fun,Xa)-funXb);
  if abs((Xi-Xb)/Xb)<tol
      Xs=Xi;
      break
  end
  Xa=Xb;
  Xb=Xi;
end
if i==n
  fprintf('solution is not in intersection %g\n',n)
  Xs=('sorry no answer');
end

I appreciate your help. I am beginner.

Answer 1

[Azzi Abdelmalek]

There is no error in your function. To call it:

fun=@(x)exp(-x)-x
Xa=0
Xb=1
tol=0.001
n=3
Xs=secantroot (fun,Xa,Xb,tol,n)

[Nasser Yari]

Thank you Azzi