(c) Given that, f is a continuous real valued function defined on the closed interval [0, 1] and x, y ∈ [0,1] Now, from Statement III, |f(x) - f(y)|≤ E|x - y| ,∀ x, y…(i) where Eq. (i) is true for real values of x + y. Let x is any real number and y is any arbitrary constant. Then, x−yf(x)−f(y)≤E and y→xy→xlimx−yf(x)−f(y)≤y→xlimE…(ii) ∴y→xlimx−yf(x)−f(y)=f′(x) From Eq. (ii) |f'(x)| = E (constant)