1. ## Maximum sale

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

2. I assume that the sales are dependent on the advertising cost, $\displaystyle x$.

The advertising cost can obviously not be negative, so that leaves you with one answer.