Solve this polynomial

1. Oct 9, 2007

Bo_

1. The problem statement, all variables and given/known data

P is profit in dollars of a particular mp3 player.

P = -76x^3 + 4830x^2 - 320000, 0 < x < 60

x is ad expense (in tens of thousands of $.) Find the smaller of two ad amounts that yield a profit of$2,500,000.

The attempt at a solution

All I can do is get this:

-76x^3 + 4830x^2 - 2,820,000 = 0

Now what do I do? I can't seem to factor. The only other way I know of is dividing by possible zeros, and I'm not feeling good about looking for the factors of 2.82 million.

2. Oct 9, 2007

Dick

I'm pretty sure it doesn't factor. Are you sure you aren't just supposed to give an approximate answer?

3. Oct 9, 2007

Bo_

I don't know but that'll have to do. There doesn't seem to be another way.

4. Oct 9, 2007

-boo boo-
sorry.

Last edited: Oct 9, 2007
5. Oct 9, 2007

Oh my apologies.....

*removes post*.

6. Oct 9, 2007

Dick

Thanks. You do get my point, right? I'm not trying to criticize your wish to help.

Last edited: Oct 9, 2007
7. Oct 10, 2007

pooface

Yea, the best I can think of is the approximate answer as well.

I just used a brute method on my calculator to narrow it down. You may want to use a graphing calculator(available online) to see what the graph looks like at least.