I'd really appreciate it if anyone can tell of if I'm on the right track!

For a maximum point, f'(x) = 0 and f"(x) < 0

Therefore:

We find the first and the 2nd derivate of the AVERAGE profit function:

P'(x) = - 6x + 1/x = 0

P"(x) = [ -6 - 1/x^2 ] < 0

IS this right so far?!!

I'm really confused.