1. Functions
Make a statement about functions. What do you notice about all 4 graphs?

2. NON-Functions
Make a statement about non-functions. What do you notice about all 3 graphs?

3. Which one is NOT a function?
Function: a relationship where each x-value has exactly one y-value
Which one is NOT a function?

4. Vertical Line Test Non-Function Function Function
If a vertical line intersects the graph more than once, the relation is NOT a function
Non-Function
Function
Function

5. Notes Each x-value has exactly One y-value
A x-value has more than one y-value
Passes the Vertical Line Test (no vertical line intersects the graph more than once)
Fails the Vertical Line Test (a vertical line intersects the graph more than once)
Students should write this in their notes before the activity.

6. Organize Cards into columns Check your answers
Activity
Cut out Cards
Organize Cards into columns
Check your answers
Glue Card in correct column
Pass out cut and paste activity to be done in NOTEBOOKS

7. 𝒚=𝟐𝒙 Equations  Functions 𝒚 = 𝒙 𝟐 𝒚 = 𝟑 𝒙 x y –3 1 27 –1 1 3 2 9 3 27
𝒚 = 𝒙 𝟐
𝒚 = 𝟑 𝒙 1. 2. 3. x y –3
1 27 –1
1 3 2 9 3 27 x y 1 2 5 10 7 14 x y –4 16 –1 1 5 25

8. Vocabulary Of A Function
Independent Variable
Dependent Variable
x-values
y-values
Domain
Range
Input
Output x
f (x)
NEW

9. 𝒚=𝟐𝒙 Function Notation f(x) 𝒚 = 𝒙 𝟐 f(x) f(x) 𝒚 = 𝟑 𝒙 x y –3 –1 2 9 3
𝒚 = 𝒙 𝟐
f(x)
f(x)
f(x)
𝒚 = 𝟑 𝒙 1. 2. 3. x y –3 –1 2 9 3 27 x y 1 2 5 10 7 14 x y –4 16 –1 1 5 25

10. Evaluate a Function using a Graph
f (x) = y 1 2 3 4 5 6 7 8 x
f (2) = 4
f (3) = 5
f (7) = 4
f (2)

11. Evaluate a Function using Algebra
f (x) = 3 x – 2
f (1) =
3(1) – 2 = 1
f (4) =
3(4) - 2
= 10
f (0) =
3(0) - 2
= -2

12. Classwork: Choose A, B or C 1 2 3 4 5 6 7 8
f (x) = x – 5
g(x) = 1.5x
f (8) = 3
g(8) = 12
f (3) = -2
g(10) = 15
g(-.5) =
f (-2)=
-.75 -7
f(2) = 4
f(0) =
f(7) = 1

13. Working Backwards
If 𝑓 𝑥 =−5𝑥+7 and 𝑓 𝑥 =−168, find 𝑥. −168=−5𝑥+7 −175=−5𝑥 𝑥=35 If 𝑓 𝑥 =3 𝑥 2 +1 and 𝑓 𝑥 =49, find 𝑥. 49=3 𝑥 =3 𝑥 2 16= 𝑥 2 𝑥=±4

14. Evaluating Functions Practice
Complete the problems on a separate sheet of paper.
Your answer should be in the form: 𝑓 7 =−3
If you need help, ask your tablemates
If 𝑓 𝑥 =𝑥+5, find 𝑓(10)
If 𝑓 𝑥 =3𝑥−9, find 𝑓(−6)
If 𝑓 𝑥 =3 4 𝑥 , find 𝑓(2)
If 𝑓 𝑥 = 𝑥 2 +6𝑥−3, find 𝑓(2)
If 𝑓 𝑥 =2 𝑥+7 −3𝑥 and 𝑓 𝑥 =13, find 𝑥
If 𝑓 𝑥 = 3𝑥 2 −11𝑥−1, and 𝑓 𝑥 =3, find 𝑥
𝑓(10)=15
𝑓 −6 =−27
𝑓(2)=48
𝑓(2)=13
𝑥=1
𝑥=4 and 𝑥=−1/3

15. Would You Rather…?
Would you rather give up television or fast food for the rest of your life?

16. Exit Slip
Complete the exit slip without using your notes When you’re done, turn it in on the grey table and work on your homework

17. Optional book practice
: 1-22, 1-66, 1-87, CL-120, 2-8, 2-102
1-41, 1-52, 1-53, 1-64, 1-70, 1-77, 1-85, CL – 126, 2-15, 2-48, 2-50
If book available
1-39, 1-69, 1-94, CL-122a, 2-7, 2-25, 2-27, 2-38
1-35, 1-36, 1- 60, 1-63, 1-91, CL – 121, 2-26, 2-105

18. Homework