I've no idea is it the right section to post this,

But I had some problems dealing with this problem.

Total costs

Market price

Tax(per unit produced)

Find:

1. Quantity to produce to maximise profits

2. What shouldtbe, so as to maximise tax revenue?

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

What I've done:

I derived the profit function as:

Then, I differentiate the profit function:

Then I'm stuck cos' I can't findx.