Math 112 5.    Unions & Intersections

  Union:  combine all the elelments of both sets

  Intersection:  choose only those elements that are in both sets.


 

Let A = {1, 2, 3, 4 }

Let B = {2, 4, 6,8}

Let U = Universe = {1,2,3,4,5,6,7,8,9,10}

A'  = the complement of A = {5,6,7,8,9,10}

 

Write the indicated set.

 

1.  A B

 

 

 

2.  A B

 

 

 

3.  (B  A) A

 

 

 

4.  (A A') B

 

 

 

5.  A' B'

 

 

 

6. B' A'

 

 

 

7.B’ A

 

 

 

8.  A (B’ A’)

 

Express the answer both graphically and in interval notation.

 

1.  x > 3 x > 5

 

 

 

2.  x > 3 x > 5

 

 

 

3. x ≤ -6  x ≥ 2

 

 

 

4.  x ≥ -3 x ≤ -8

 

 

 

5.  2 ≤ x < 4 x ≥ 4

 

 

 

6.  2 ≤ x ≤ 4 x ≥ 4

 

 

 

7.  1 < x < 3 2 ≤ x < 7

 

 

 

8.  -4 < x ≤ 5 0 ≤ x < 8

 

 

 

Write as a single interval if possible

 

1.  [3 , 5) ( 1 , 7]

 

 

2.  ( -4 , 2] ( 1 , 3]

 

 

3.  (-∞, 4] (0, 8]

 

 

4.  ( -∞, -3] (-10, ∞ )

 

 

5.  (∞ , 6] [3, ∞)