4.2 Patterns and linear functions

Dependent variable It changes in response to another variable. It isalso the “y” variable

Independent variable The variable “in charge”. It is also the “x” variable.

Inputs:

Outputs: Values of the dependent variable

Values of the independent variable

# of rectangles Perimeter Ordered pair (x,y)1

2

3

4

2(1) + 2(6) = 14

2(2) + 2(6) = 16

2(3) + 2(6) = 18

2(4) + 2(6) = 20

(1,14)

(2,16)

(3,18)

(4,20)

Equation: y= 2x + 12

Words: Two times the number of rectangles plus 12 equals the perimeter.

Graph:

Function: A relationship that pairs each input value (x) with exactly one output (y) value.

Linear function: a function whose graph is a nonvertical line.

Words: The amount of memory left is 512 minus 3 times the number of photos taken.

What do you notice when x = 0?

What do you notice about the independent variable?

What do you notice about the dependent variable?

Equation: y = -3x + 512 OR y = 512- 3x

graph:

Assignment: page: 243: 6-13, 15, 17, 22