Question

relations & functions
part 1: relations & functions

1. {(8,2),(4,−1),(0,−1),(−4,2)}

domain: _______________
range: _______________
function? _______
2.

x	y
-1	-4
2	-2
7	9
-1	-3

domain: _______________
range: _______________
function? _______
assorted answers for domain and range:
(not all will be used & the all real numbers will be used more than once)
all real numbers
x ≤ 0
x ≥ 0
y ≤ 1
x ≤ 1
−2 ≤ x ≤ 6
−1 ≤ x ≤ 3
y ≥ 3
y ≤ 3
−3 ≤ y ≤ 2
y ≤ 2
x ≥ −1

1. graph

domain: _______________
range: _______________
function? _______
x-int(s): _______________
y-int: _______________
find f(4): _______

1. graph

domain: _______________
range: _______________
function? _______
x-int(s): _______________
y-int: _______________
when f(x) = −4, find x: _______

1. graph

domain: _______________
range: _______________
function? _______
x-int(s): _______________
y-int: _______________
find f(−2): _______

1. if f(x) = −2x + 7, find f(x) = 8.
2. find the range of the function f(x) = x² − 6x if the domain is {−7, −2, 1}.

Explanation:

Step1: Set equation for f(x)=8

$$-2x + 7 = 8$$

Step2: Solve for x

Subtract 7: $-2x = 1$; Divide by -2: $x = -\frac{1}{2}$

Step1: Calculate f(-7)

$$f(-7)=(-7)^2 -6(-7)=49 +42=91$$

Step2: Calculate f(-2)

$$f(-2)=(-2)^2 -6(-2)=4 +12=16$$

Step3: Calculate f(1)

$$f(1)=(1)^2 -6(1)=1 -6=-5$$

Step4: List range values

Range is {-5,16,91}

Answer:

$-\frac{1}{2}$