Standard: SWBAT understand relation and a function;
determine if a given relation defines a function
Mini Quiz 35
1. Is this relation a function: {(5, 3), (-2, 3), (5, 3), (4, 3)}?
Explain.
2. Find the domain and range of the relation in problem 1.
3. Is this relation a function? Explain.
Quick Review
1. How do you find the domain and the range?
Domain are the x’s, Range are the y’s
2. How do you tell if a relation is a function?
“Every x has only one y”. Check if x repeats/the vertical line test.
3. a) Is this a function? Why? {(3, 0), (-2, 1), (0, -1), (-3, 2)}
Yes, x doesn’t repeat.
b) Find the domain and range.
Domain: 3, -2, 0, -3
Range: 0, 1, -1,2
4. a) Is the table a function? Why?
No, x repeats and you get two different y
b) Find the domain and range.
Domain: -3, 6, 8
Range: -5, 7, 4, -2
Evaluating a Function Rule
The notation f(x) is the same as y (i.e. f(x) = y)
1. Evaluate f(x) = -3x – 10 for the domain {6}
f(6) = -3(6) – 10
f(6) = -18 – 10
f(6) = -28
Evaluating a Function Rule
The notation f(x) is the same as y (i.e. f(x) = y)
2. Evaluate f(x) = -x – 6 for the domain {-4}
f(-4) = -(-4) – 6
f(-4) = 4-6
f(-4) = -2
Evaluating a Function Rule
The notation f(x) is the same as y (i.e. f(x) = y)
3. Evaluate f(x) = x – 10 for the domain {-2}
f(-2) = (-2) – 10
f(-2) = -1 – 10
f(-2) = -11
Graphing Equations using a
Table
Directions:
1. Pick a number to plug in for x (usually “0”)
2. Replace the x and calculate y
3. Graph the ordered pair
4. Repeat steps 1 - 3 at least 2 more times (to get the
shape of the graph)
5. Connect the points to draw the graph
Using Tables
Find the domain and range.
4. Model the function rule y = 2x - 3
x
2x - 3
y
0
2(0) – 3 = 0 – 3
-3
1
2(1) - 3 = 2 – 3
-1
-1
2(-1) - 3 = -2 – 3
-5
Using Tables
Find the domain and range.
5. Model the function rule f(x) = - 2x + 5
x
-2x + 5
f(x)
Using Tables
Find the domain and range.
6. Model the function rule y = - x + 1
x - x+1
y
Domain and Relations
Graph the function and determine the domain and
range.
7. y = |x|
Domain and Relations
Graph the function and determine the domain and
range.
8. f(x) =
x
Wrap Up
 Evaluating Function
 Using a Table to Graph
 Determining Domain and Function
 Determining Domain and Range
HW: P. 190 #1-17 odd, 21, 25, 61-67 all
DLUQ: What do you need to make to graph a function?