2. Un objeto es lanzado hacia arriba y luego de 4 s tiene una rapidez de 10 m/s. Determine con qué rapidez se lanzó. (g = 10 m/s2)

The x-intercepts represent the number of notebooks sold that will produce a break-even situation, that is, no profit will be generated.
The maximum value tells us that the profit is maximum when 2 notebooks are sold and its value is $300.
The graph increases from (0 , 2) and decreases from (2 , 0). This means that as the sales of notebooks approach 2, they start to increase and they start decreasing after 2. (negative values omitted because negative number of notebooks can not be sold.)