Which of these statements is/are true? (Select all that apply.) If F(x) = f (x) . g(x), then F '(x) = f (x) . g'(x) + g(x) . f'(x) If c is a constant, then dx If F(x) = f (x) + g(x), then F '(x) = f'(x) +g'(x) If k is a real number, then d(x ) = k-1 dx none of these O If F(x) = f (x) . g(x), then F '(x) = f '(x) g'(x) If c is a constant, then d dx ( c . f ( x ) ) =c. (f ( x) ) X