1. Daily Problem for Tuesday 10/11/16

2. 3.1 Representing Proportional Relationships
Essential Question:
Page 71
How can you use tables, graphs, & equations to represent proportional situations?

3. Materials needed Textbook Pencil Highlighter(s) Calculator
Whiteboard/marker

4. Colin Berg, Expert Fry-man

5. Proportional Relationship
a relationship between two quantities (numbers) in which the ratio (division) of one quantity (output) to the other quantity (input) is constant page 72
Example: Colin works at Wendy’s for 8 hours (input) on Sunday and earns $72 (output). He works on Tuesday for 5 hours (input) and earns $45 (output). This represents a proportional relationship because $72/8hrs = $9.00 per hour and $45/5hrs = $9.00 per hour

6. Constant of Proportionality (k)
In a proportional relationship, when the output (y) is divided by the input (x) the result is known as the constant of proportionality (k) page 72
Example: Colin’s hourly rate ($9.00 per hour) is the constant of proportionality (k)
The equation y ÷ x = k can be used to find the C of P (k)
Once the C of P is found, it can be used to find the output for any input using the equation y = kx

7. Example 1, page 72 Number of hrs 1 2 4 8 Amount earned 12 24 48 96
To find k, divide the amount earned (output) by the number of hours (input)
12÷1= ÷2=12 48÷4=12 96÷8=12 k=12
To find amount earned for any # of hours, use the equation y=12x

8. Your Turn page 72

9. Representing Proportional Relationships with Graphs page 73
A Proportional Relationship on a graph must:
Be a straight line
Pass through the origin (0,0)
What is the C of P?
Time (x) 2 4 6 8 10
Miles (y) 92
184
276
368
460

10. Your Turn page 73

11. Textbook Assignment
#1-6 page 74
Answers in Selected Answers page SA3

12. Worksheet Assignment