The total revenue in Rupees received from the sale of x units of a product is
given by
R(x) = 3x2 + 36x + 5 The marginal revenue, when x = 15 is
(A) 116
(B) 96
(C) 90
(D) 126
6 3  Increasing and Decreasing Functions
In this section, we will use differentiation to find out whether a function is increasing or
decreasing or none Consider the function f given by f (x) = x2, x ∈ R