Suppose the function f(x) = 9x2 − 2x + 6 describes a physical situation that makes sense only for whole numbers between 0 and 10. For what value of x does f reach a maximum, and what is the maximum value? (Suggestion: We suggest beginning with a table starting at 0 with a table increment of 1 and then panning further down the table.)

A company that produces cellular phones analyzes its production and finds that the profit P (in dollars) on the sale of the phones is approximated by the function: P(x)=-0.2x2+460x-25,000 where x is the number of phones produced each month. How many phones per month should be made so as to maximize profit? And what is the maximum profit?