A combination of bisection and secant method

Hello! So I have to write a program on Matlab using both the bisection and secant method in one. I'm super new to Matlab and this is the code I managed to figure out. The program tells me that when I call a function, I have to use parentheses. But I don't see where I should put that. I've also attached the required steps for the program. Thank you!

function p = bisection(f, a, b, tol)
w=1;
for i=1:100
    p= a +(w*f(a)*(a-b)/f(b)-w*f(a));
    fprintf(a,b,p,f(p));
    if f(p)*f(b)>0
        w=0.5;
    else
        w=1;
        a=b;
    end
    b=p;
    if abs(b-a)<tol || abs(f(p))<tol
        break;
    end
end

[Lavorizia Vaughn]

I think you just need to out parents around the p in function p