what's wrong here? I have copied this code from my textbook and it's not working

Help me here plz:

------------------------------------------------

function xb=insearch(func,xmin,xmax,ns)
if nargin <4;
    ns=50;
end
x=linspace(xmin,xmax,ns);
f=func(x);
nb=0;
xb=[];
for k=1:length(x)-1;
    if sign (f(k))~=sign(f(k+1))
    nb=nb+1;
    xb(nb,1)=x(k);
    xb(nb,2)=x(k+1);
    end
end
if isempty(xb)
    disp('no brackets found')
    disp('check interval or increase ns')
else
    disp('number of brackets:')
    disp(nb)
end

and In the command window:

insearch (@x sin(10*x)+cos(3*x),xmin,xmax,ns)

and am getting the following error:

Error: Unexpected MATLAB expression.

Answer 1

[Walter Roberson]

insearch (@(x) sin(10*x)+cos(3*x),xmin,xmax,ns)

notice I changed the @x to @(x)

Answer 2

[Ahmet Cecen]

Your problem is here:

 insearch (@x sin(10*x)+cos(3*x),min,max,ans)

It is NOT:

 @x sin(10*x)+cos(3*x)

It is:

 @(x) sin(10*x)+cos(3*x)

[B]

Thank you very much for your help