Anyone now how to do this problem i'm lost on it?

The profit function P(x) is a parabola.

To find the maximum profit, you need the vertex of the parabola.

The vertex can be found using the formula 

where a = -.001 , b = 3,  c = -1800



Part a) Profit is maximized when x = 1500.

To find Profit, plug 'x' into profit function.


Part b)  Daily max Profit is $450

Next to find the break even point, when profit = 0.

Set profit function equal to 0 and solve for 'x'.

This is a quadratic equation, so use the quadratic formula.



Finally, the avg rate of change is simply the slope of the line between 2 points on the parabola.  Use slope formula.



Part d)  Avg rate of change = -3/10