Linear Functions

Linear Functions

SWBAT: Find the Rate of Change (slope) given two points, a line in y-intercept form, and a graph.

Take a look at Picture and describe what you see.

Linear Function

• A Straight Line

• Constant Slope

• Slope-Steepness of a line

Finding Slope given two points

•  $\ m\ =\frac{y_2-y_1}{x_2-x_1}$  -Slope Formula

• The change in y over the change in x

• 
  

Multiple Choice

What's the slope of the line that passes through (2, -1) and (2, -5)

• 1/2
• Zero
• 3
• Undefined

Multiple Choice

What's the slope of a line that goes through the point (2, 4) and has a y-intercept of 3

• Zero
• 2
• 1/2
• Undefined

Multiple Choice

Find the slope given the following points:
(-1, 2) (3, 5)

• Zero
• 7/4
• 3/4
• undefined

Multiple Choice

Find the slope when given (2, 3) (3, 5)

• 1/2
• 2
• -2
• 4

Undefined Slope

Sometimes the "X" value is the same (creates a vertical line)

Zero Slope

Sometimes the "y" value is Zero

Multiple Choice

Find the slope of the line that passes through 
(17, 2) and (17, -3)

• m=0
• m=undefined
• m=5
• m=-5

Multiple Choice

Find the slope of the line.

• Undefined
• 0
• 1
• -1

Multiple Choice

What is the slope in the picture?

• Positive
• Negative
• Zero
• Undefined

Slope-intercept form of a line

•  $y\ =\ mx\ +\ b$  

• m= slope

• b= y-intercept

Multiple Choice

How would you write the equation with a slope of 2/3 and a y-intercept of -3

• y=3/2x+3
• y=2/3-3
• y=2/3x-3
• y=2/3x+3

Multiple Choice

Determine the slope and y-intercept.         y = 3/2x + 3

• slope: 5   y-intercept:  (0,3) 
• slope: 3/2   y-intercept:  (0,3) 
• slope:  4  y-intercept:  (0,3/2)
• slope: 1/5   y-intercept:  (0,5) 

Multiple Choice

Which Graph is Linear?

• 1st
• 2nd
  2nd
• 3rd
• None

Multiple Choice

Which value is the y-intercept in the equation:

y= 2x -2

• 2

• -2

• 1

Multiple Choice

Which value is the slope in the equation:

y= 4x + 2

• 4

• 2

• x

Slope from a Graph

Rise/Run

Multiple Choice

Find the slope

• -3/4
• 4/3
• 3/4
• -4/3

Multiple Choice

Find the slope

• 4/5
• 5/4
• -5/4
• -4/5

Multiple Choice

Find the slope

• 2
• -2
• 1/2
• -1/2

Open Ended

Briefly describe what is meant by slope of a line.