Given cost function is
c(x) = [tex]2.1 + 0.12x - 0.0001x^2[/tex] (20 ≤ x ≤ 400)
where x is the number of thousands of square feet
total revenue will be $0.2 million dollars per thousand square feet
Revenue is 0.2 millions per thousand square feet. we know x is the number of thousand of square feet
So R(x) = 0.2x
We know Profit = Revenue - Cost
P(x) = R(x) - C(x)
[tex]P(x) = 0.2x - (2.1 + 0.12x - 0.0001x^2)[/tex]
[tex]P(x) = 0.2x - 2.1 - 0.12x + 0.0001x^2)[/tex]
combine like terms
[tex]P(x) =-2.1 + 0.08x + 0.0001x^2[/tex]
Profit function is
[tex]P(x) =0.0001x^2 + 0.08x - 2.1[/tex]