1. Relations and Functions
ALGEBRA 1 LESSON 5-2
Find the domain and the range of the ordered pairs.
age weight
domain: {12, 14, 16, 18} List the values in order. Do not repeat values.
range: {110, 120, 124, 125, 126}
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2. Relations and Functions
ALGEBRA 1 LESSON 5-2
Determine whether each relation is a function.
a. {(4, 3), (2, –1), (–3, –3), (2, 4)}
The domain value 2 corresponds to two range values, –1 and 4.
The relation is not a function.
b. {(–4, 0), (2, 12), (–1, –3), (1, 5)}
There is no value in the domain that corresponds to more than one value of the range.
The relation is a function.
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3. Relations and Functions
ALGEBRA 1 LESSON 5-2
a. Evaluate ƒ(x) = –5x + 25 for x = –2.
ƒ(x) = –5x + 25
ƒ(–2) = –5(–2) + 25 Substitute –2 for x.
ƒ(–2) = Simplify.
ƒ(–2) = 35
b. Evaluate y = 4x2 + 2 for x = 3.
y = 4x2 + 2
y = 4(3)2 + 2 Substitute 3 for x.
y = 4(9) + 2 Simplify the powers first.
y = Simplify.
y = 38
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4. Relations and Functions
ALGEBRA 1 LESSON 5-2
Evaluate the function rule ƒ(g) = –2g + 4 to find the range for the domain {–1, 3, 5}.
ƒ(g) = –2g + 4
ƒ(–1) = –2(–1) + 4
ƒ(–1) = 2 + 4
ƒ(–1) = 6
ƒ(g) = –2g + 4
ƒ(3) = –2(3) + 4
ƒ(3) = –6 + 4
ƒ(3) = –2
ƒ(g) = –2g + 4
ƒ(5) = –2(5) + 4
ƒ(5) = –10 + 4
ƒ(5) = –6
The range is {–6, –2, 6}.
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5. Relations and Functions
ALGEBRA 1 LESSON 5-2
1. a. Find the domain and range of the ordered pairs (1, 3), (–4, 0), (3, 1), (0, 4), (2, 3).
b. Use mapping to determine whether the relation is a function.
domain: {–4, 0, 1, 2, 3} range: {0, 1, 3, 4}
The relation is a function.
2. Find the range of the function ƒ(g) = 3g – 5 for the domain {–1.5, 2, 4}.
{–9.5, 1, 7}
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