Functions Domain and Range
Rucete Mathematics In a Nutshell
Domain definition
The domain is the first or x-value set of each ordered pair.
Range definition
The range is the set of second or y-values of each ordered pair.
Example
state the domain and range of the following functions.
1. {(2 , 1), (3 , 2), (4 , 2), (5 , 3)}
Domain = {2, 3, 4, 5}
Range = {1, 2, 3} (not to repeat 2)
2. y = x^2 + 1
Domain = R
Range : y ≥ 1 or [1,∞)
Practice
(When you solve a practice question, you can get a little more used to this concept.)
State the domain and range of the following functions.
1. {(2, 3), (3, 9), (3, 10), (4, 11)}
Domain:
Range:
2.
Domain :
Range :
Answer
1.
Domain: {2, 3, 4}
Range: {3, 9, 10, 11}
2. y = √x+3
Domain: x ≥ -3 or [-3, ∞)
Range: y ≥ 0 or [0, ∞)