15.2. Methods of Expressing a Set

Try these first

1. 1.

   Define the term 'empty set'.

   Hint

   Think about a set that has zero members.

2. 2.

   Give an example of a singleton set.

   Hint

   Remember, it has only one item.

3. 3.

   What is the roster method?

   • A method that describes properties
   • A method that lists elements
   • A method that counts elements

   Hint

   Think about how elements are presented in this method.

4. 4.

   True or False: The empty set is a subset of every set.

   • True
   • False

   Hint

   Consider what it means to have no elements.

5. 5.

   Given a set S = {2, 4, 6, 8}, find its power set and explain the reasoning.

   Hint

   Remember, each element can be present or absent in a subset.

6. 6.

   If a set has a cardinality of 5, how many subsets can you expect to find in its power set?

   Hint

   Think about powers of 2 relating to the total number of combinations.