I assume that the sales are dependent on the advertising cost, .
The advertising cost can obviously not be negative, so that leaves you with one answer.
How much should be spent on advertising to maximize sales? What is the maximum sales level?
S(x) = 200x + 1,500 / 0.02x^2 + 5
critical point is 10 and -25
For maximum sale of 500 units
this is what I have I just dont know what to plug in for advertising cost