The given function f is f (x) = x3 -5x2-3x
f, being a polynomial function, is continuous in [1, 3] and is differentiable in (1, 3)
whose derivative is 3x2 − 10x − 3.

Mean Value Theorem states that there exist a point c∈ (1, 3) such that f' (c) =-10

Hence, Mean Value Theorem is verified for the given function and c= 7/3 ∈ (1,3) is the only point for which f ' (c) =0