Graph each function. (See Examples 1 and 2.)f(x) = [x − 3]Example 1Graph the greatest−inte...

Graph each function. (See Examples 1 and 2.)

f(x) = [x − 3]

Example 1

Graph the greatest−integer function f(x) = [x].

Example 2

In 2013, the U.S. Post Office charged to ship a flat envelope first class to Eastern Europe, Europe, or Australia a fee of $2.05 for up to and including the first ounce, $.85 for each additional ounce or fraction of an ounce up to and including 8 ounces, and then $1.70 for each additional four ounces or less, up to a peak of 64 ounces. Let D (x) represent the cost to send a flat envelope weighing x ounces. Graph D (x) for x in the interval (0, 20].