3. Blackberry is also in the business of selling phones. The data for the profit that Blackberry makes on selling tablets is represented by the following equation with profit being P(b) and b being number of blackberry phones sold (both variables in millions): P(b) = -x2 + 8x – 8

a. Use the quadratic formula to solve the equation. What do these points tell us about the graph?

b. Complete the following table. Based on the table, estimate the vertex for the function. Is the vertex a max. or a min. point?

Blackberry: Profit from Smart Phones Sold

Smart Phones sold (in millions) b Profit (in millions of dollars) P(b)
-1
0
2 4
3
4
5 7
6

c. Sketch a graph for Blackberry. Label the x and y axis (for b and P(b))