Chapter 1.8, Problem 9C

Each object in a set is called an element or a member of a set. One method of describing a set is called the roster method, in which elements are listed between braces, with commas between the elements. The order in which we list elements isn’t important: are the same set.

Often, we will name sets by using a capital letter. We might name the set of objects in the left circle in the diagram in Question 2 using the letter A.

Use the roster method to list the elements of the left circle: $\mathrm{A\; <mo>\; =\; <mrow>\; <mo>\; \{\; <mrow>\; <mo>\; \_\; <mo>\; \_\; <mo>\; \_\; <mo>\; \_\; <mo>\; \_\; <mo>\; ,\; <mtext>\; \; <mo>\; \_\; <mo>\; \_\; <mo>\; \_\; <mo>\; \_\; <mo>\; \_\; <mo>\; ,\; <mtext>\; \; <mo>\; \_\; <mo>\; \_\; <mo>\; \_\; <mo>\; \_\; <mo>\; \_\; <mo>\; ,\; <mtext>\; \; <mo>\; \_\; <mo>\; \_\; <mo>\; \_\; <mo>\; \_\; <mo>\; \_\; <mo>\; \}\; </mo>\; </mo>\; </mo>\; </mo>\; </mo>\; </mo>\; </mtext>\; </mo>\; </mo>\; </mo>\; </mo>\; </mo>\; </mo>\; </mtext>\; </mo>\; </mo>\; </mo>\; </mo>\; </mo>\; </mo>\; </mtext>\; </mo>\; </mo>\; </mo>\; </mo>\; </mo>\; </mo>\; </mrow>\; </mo>\; </mrow>\; </mo>}$