Solve please!

[hodan123]

A computer software company models the profit on its latest video game using relation P= -4x^2+20x-9, where x is the number of games produced in the hundred thousands and p is the profit.

a) what is the maximum profit that the company can earn? (how did you find this)
b) how many games must the company produce to earn the maximum profit? (how did you do this).

 

[tkhunny]

It's kind of a funny question. It is quite likely that you will be answering b) before answering a).

What do you know of parabolas? Solve P(x) = 0 and see what two values you get for 'x'. This may lead you in a good direction. This will also help establish rational Domain limitations.