Exponential functions

Question

The profit of an organization is calculated by the function            P(x) = x² - 4000x + 7800000, where x is the Number of units sold. if the net profit is 3800000, find the number of items sold.

Answer 1

That's just a matter of solving the equation:

 

x² - 4000x + 7800000 = 3800000

 

x² - 4000x + 4000000 = 0

 

(x-2000)(x-2000) = 0

 

x = 2000

 

So 2000 items were sold.