1. OBJECTIVE: How do we use functions
to find output values?
Do Now
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2. Anticipatory Set
The Self­Operating Napkin: As you raise spoon of soup (A) to your mouth it pulls string (B), thereby
jerking ladle (C) which throws cracker (D) past parrot (E). Parrot jumps after cracker and perch (F)
tilts, upsetting seeds (G) into pail (H). Extra weight in pail pulls cord (I), which opens and lights
automatic cigar lighter (J), setting off sky­rocket (K) which causes sickle (L) to cut string (M) and allow
pendulum with attached napkin to swing back and forth thereby wiping off your chin.
QUESTION: Why is this cartoon funny?
Function: a mathematical procedure that operates according to a rule
to produce a single output value for each input value.
QUESTION: Explain how the Rube Goldberg cartoon uses an input, an
output, and a rule.
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3. Today‛s functions will be shown as equations with two
variables.
y = 2x + 9
QUESTION: Explain how to use the rule above if the input
value was 4.
QUESTION: How did you know the procedure?
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4. Think-Pair-Share Activity: y = 3x
1.) Complete the function table individually.
2.) Discuss with your partner until agreement.
Input Rule Output
x y
-2
-1
0
1
2
4

5. Think-Pair-Share Activity: y = 2x + 9
1.) Complete the function table individually.
2.) Discuss with your partner until agreement.
Input Rule Output
x y
-2
-1
0
1
2
5

6. Think-Pair-Share Activity:
y = 3x - 4
1.) Complete the function table individually.
2.) Discuss with your partner until agreement.
Input Rule Output
x y
-2
-1
0
1
2
6

7. Think-Pair-Share Activity:
y = 4x2
1.) Complete the function table individually.
2.) Discuss with your partner until agreement.
Input Rule Output
x y
-2
-1
0
1
2
7

8. BEFORE YOU LEAVE
Explain the relationship between the cartoon from
the Anticipatory Set and functions.
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9. Mr. Tjersland's Math 7
Homework: Pages 606-607 #1-3 all, 16, 18-21 all
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