College Algebra, 2013a

1.3 Introduction to Functions 53
1.3.2 Answers
1. Function
domain = {−3, −2, −1, 0, 1, 2 ,3}
range = {0, 1, 4, 9}
3. Function
domain = {−7, −3, 3, 4, 5, 6}
range = {0, 4, 5, 6, 9}
2. Not a function
4. Function
domain = {1, 4, 9, 16, 25, 36,...}
= {x | x is a perfect square}
range = {2, 4, 6, 8, 10, 12,...}
= {y | y is a positive even integer}
5. Not a function 6. Function
domain = {x | x is irrational}
range = {1}
7. Function
8. Function
domain = {x|x =2 n for some whole number n} domain = {x | x is any integer}
range = {y | y is any whole number}
range = { y | y = n 2 for some integer n }
9. Not a function 10. Function
domain = [−2, 4), range = {3}
11. Function
domain = (−∞, ∞)
range = [0, ∞)
13. Function
domain = {−4, −3, −2, −1, 0, 1}
range = {−1, 0, 1, 2, 3, 4}
15. Function
domain = (−∞, ∞)
range = [1, ∞)
17. Function
domain = [2, ∞)
range = [0, ∞)
12. Not a function
14. Not a function
16. Not a function
18. Function
domain = (−∞, ∞)
range = (0, 4]
19. Not a function 20. Function
domain = [−5, −3) ∪ (−3, 3)
range = (−2, −1) ∪ [0, 4)