CONCEPT PREVIEW Fill in the blank(s) to correctly complete each sentence. The set containing no elements is the _______, symbolized _______.

Determine the largest open intervals of the domain over which each function is (c) constant. See Example 8.

Determine the intervals of the domain over which each function is continuous. See Example 9.

List the elements in each set. See Example 1. {x|x is a whole number less than 6}

List the elements in each set. See Example 1. {z|z is a natural number greater than 4}

List the elements in each set. See Example 1. {z|z is an integer less than or equal to 4}

List the elements in each set. See Example 1. {a|a is an even integer greater than 8}