Matlab Program for finding positive root of a Non-Linear Function using Regula-Falsi Method

k=input('Enter the function =  ', 's');
f= inline(k);
a=0; b=1;
for i=1:inf
    if f(a)*f(b)<0
        break
    else
        a=a+1;
        b=b+1;
    end
end
for i=2:inf
   x(i)= (a*f(b)-b*f(a))/(f(b)-f(a));
   if f(x(i))*f(a)<0
       b=x(i);
   else
       a=x(i);
   end
   if abs(x(i)-x(i-1))<=0
      Iteration=i-1
      Root=x(i)
      break
   end
end