function [xnew,step]=kokbulma(xleft,xright)
f=inline('x*(exp(x))-cos(x)','x');
a=xleft; b=xright; step=1;
xnew=(a+b)/2; fa=f(a);
error=100;
while (error>0.005)
fnew=f(xnew);
if sign(fnew) == sign(fa)
a = xnew;
fa = fnew;
else
b = xnew;
fb = fnew;
end
step=step+1; x_old=xnew; xnew=(a+b)/2;
error=abs(xnew-x_old)/xnew*100;
end
return;
end