An entertainment services provider on the internet has 10000 subscribers paying $15 per month. It can get 1000 more subscribers for each $1 decrease in the monthly fee. Determine the monthly fee that will yield the maximum monthly revenue and the value of that revenue

Monthly fee that will yield the maximum monthly revenue is  $12.5

Then the value of the maximum monthly revenue is $156 250

Step-by-step explanation:

x   - value of decrease

1000x   - number of new subscribers for $x decrease

10000+1000x  - number of subscribers after $x decrease in the monthly fee

15-1x      the monthly fee after $x decrease

f(x) = (10000 + 1000x)(15 - x)           ← quadratic function

For quadratic function given in standard form:  f(x) =a(x-h)²+k  where a<0 the f(x)=k is the maximum value of function, and occurs for x=h

Expressing given function to standard form:

f(x) = 1000(10 + x)(15 - x)

f(x) = 1000(150 - 10x + 15x - x²)

f(x) = 1000(-x² + 5x + 150)

f(x) = -1000x² + 5000x + 150000                          {a=-1000<0}

15-2.5 = 12.5