(a)
A
∪
B
=
A
True if
A
= {
w
} and
B
= {
w
}.
(b)
A
∩
B
=
A
True if
A
= {
w
} and
B
= {
w
}.
26. With
A
and
B
as in Exercise 25, find (
A
×
A
) ∩ (
B
×
B
).
(
A
×
A
)
=
{(a, a), (a, b), (a, c), (b, a), (b, b), (b, c), (c, a), (c, b), (c, c)}
(
B
×
B
)
=
{(a, a), (a, b), (a, d), (b, a), (b, b), (b, d), (d, a), (d, b), (d, d)}
(
A
×
A
) ∩ (
B
×
B
)
=
{(a, a), (a, b), (b, a), (b, b)}
Section 1.2 (pages 17-19)
2a. Let
A
,
B
, and
C
be subsets of a set
U
. Which of the following Venn diagrams
illustrates the set (
A
∩
B'
)
∪
B
?
Venn diagram
a
above is correct.
2b. Let
A
,
B
, and
C
be subsets of a set
U
. Which of the following Venn diagrams
illustrates the set
A
∩
B
∩
C'
?
Venn diagram
c
above is correct.