1. For functions f : X → R and g : X → R, we have
2. (f + g)(x) = f (x) + g(x), x ∈ X
3. (f – g)(x) = f (x) – g(x), x ∈ X
4. (f.g)(x) = f(x) . g(x), x ∈ X
5. (kf)(x) = k (f (x) ), x ∈ X, where k is a real number.
6. (f/g)(x) = f(x)/g(x) x ∈ X, g(x) ≠ 0
