Chapter 3 - Section 3.1 - Quadratic Functions and Models - 3.1 Exercises - Page 253: 53

Max. revenue $R(x)= 4000$ units manufactured $x= 100$

Calculate the maximum of the function by substituting the values from the function into $x_{MAX}=\frac{-b}{2a}\rightarrow x_{MAX}=100$ which is the number of products manufactured. Then substitute $x=100$ into the function to get the maximum revenue.