82
Chapter Two FUNCTIONS
Exercises and Problems for Section 2.2
Skill Refresher
In Exercises S1–S4, for what value(s), if any, are the functions
Solve the inequalities in Exercises S5–S12.
undefined?
S5. x
8 > 0
x + 5 > 0
S6.
x
2
1
S1. f (x) =
S2. g(x) =
x
3
x(x
3)
3(n
4) > 12
S8. 12 ≤ 24
4a
S7.
√
√
S3. h(x) =
x
15
S4. k(x) =
15
x
2
2
S9. x
25 > 0
S10. 36
x
≥ 0
2
2
2
2
S11. 12
2a
≤ a
S12. y
3 > 15
y
Exercises
2
In Exercises 1–4, estimate the domain and range of the func-
7. f (x) = x
4,
2 ≤ x ≤ 3
√
tion. Assume the entire graph is shown.
8. f (x) =
9
x
2
,
3 ≤ x ≤ 1
1.
2.
In Exercises 9–18, find the domain of the function alge-
18
3
f (x)
braically.
f (x)
1
1
9. f (x) =
10. p(t) =
6
1
x + 3
t
2
4
2
t
3
1
x
x
11. f (t) =
12. n(q) =
1
7
2
6
3t + 9
q
4
+ 2
1
1
y
y
3.
4.
13. f (x) =
√
14. y(t) =
t
4
9 + x
5
6
4
5
3
15. f (x) =
x
2
4
16. q(r) =
r
2
16
f (x)
4
3
√
f (x)
3
2
2
4
17. m(x) = x
9
18. t(a) =
a
2
2
1
1
x
x
1 2 3 4 5
1 2 3 4 5
In Exercises 19–22, find the domain and range of the function
algebraically.
In Exercises 5–8, use a graph to find the range of the function
on the given domain.
√
1
19. m(q) =
q
4
20. f (x) =
15
4x
5
1
5. f (x) =
,
2 ≤ x ≤ 2
x
1
1
21. f (x) =
√
22. f (x) =
√
1
x
4
9
x
6. f (x) =
,
1 ≤ x ≤ 1
x
2
Problems
In Problems 23–26, you are given the domain D of the func-
27. Give a formula for a function that is undefined for x =
tion. Where applicable, find possible values for the constants
2 and for x <
4, but is defined everywhere else.
a and b.
28. Give a formula for a function whose domain is all nega-
1
tive values of x except x =
5.
23. f (x) =
, D: all real numbers = 3
x
a
29. A restaurant is open from 2 pm to 2 am each day, and a
1
maximum of 200 clients can fit inside. If f (t) is the num-
24. p(t) =
, D: all real numbers except 4
(2t
a)(t + b)
ber of clients in the restaurant t hours after 2 pm each day,
and 5.
what are a reasonable domain and range for f (t)?
25. n(q) =
q
2
+ a, D: all real numbers
√
26. m(r) =
r
a, D: all real numbers ≥
3