mac ex6 c

f=@(x)(x-cos(x));
fprintf("root=%.6f\n", findroot(f, -1000, 1000))

function root = findroot(f, a, b)
    if f(a) * f(b) > 0
        root = NaN;
        return
    end

    TOL = 1E-6;
    while (b - a) / 2 > TOL
        mid = (a + b) / 2;

        if f(a) * f(mid) <= 0
            b = mid;
        else
            a = mid;
        end

        root = mid;
    end
end