Effective May 11, 2009, the cost of mailing a first-class letter was 44 cents for the first ounce and 17 cents for each additional ounce or fraction of an ounce. Let P(w) be the postage required for mailing a letter weighing w ounces, for 0 ≤ w ≤ 3.

a. Describe P(w) as a piecewise-defined function.

b. Sketch the graph of P.