## Thinking Mathematically (6th Edition)

$A \cap C'= \left\{b, c, d\right\}$
RECALL: (1) The complement of set A, represented by $A'$, is the set that contains all the elements of the universal set $U$ that are not elements of $A$. (2) $\cap$ represents intersection of sets. The intersection of two sets is a set that contains all the elements that are common to the two sets. To find the elements of the given set, you have to (i) find the complement of $C$ then (ii) find the intersection of A and $C'$ afterwards. Note that: $C'=\left\{b, c, d, f\right\}$ Thus, $A \cap C'= \left\{a, b, c, d\right\} \cap \left\{b, c, d, f\right\} = \left\{b, c, d\right\}$