Lines Part 1
 y = mx + b

Enter m = 1, b = 0   
gives y = 1x + 0  or  y = x
m = slope      b = y intercept  i.e.
(0, b)

Click Graph, then Click Store.
Use this graph to compare 

1 . Enter m = 1,  b = -2  

Predict which way the graph will SHIFT?
Up None
Down

Now click Graph.

2. Enter m = 1,  b = 2 

Predict which way the graph will SHIFT?
Up None
Down

Now click Graph.

3. Enter m = 1, b = -3/2 

Predict which way the graph will SHIFT?
Up None
Down

Now click Graph.
Linear Part 2
 y = mx + b

Enter m = 1,  b = 0   
gives y = 1x + 0  or y = x
m = slope      b = y intercept  i.e.
(0, b)

Click Graph, then Click Store.
Use this graph to compare 

1 . Enter m = 1, b = 2/5 

Predict which way the graph will SHIFT?
Up None
Down

Now click Graph.

2. Enter m = 1, b = -8 (change window to fit) 

Predict which way the graph will SHIFT?
Up None
Down

Now click Graph.

3. Enter m = 1, b = 9 (change window to fit)

Predict which way the graph will SHIFT?
Up None
Down

Now click Graph.
Lines Quick Quiz
Without graphing predict which way the graph will shift from  y = x

 1.  y = x + 3  

Predict which way the graph will SHIFT?
Up 3 None
Down 3

Verify with grapher

 2.  y = x - 3

Predict which way the graph will SHIFT?
Up 3 None
Down 3

Verify with grapher

 3.  y = x - 2/3

Predict which way the graph will SHIFT?
Up 2/3 None
Down 2/3

Verify with grapher

 4.  y = x + 5/4

Predict which way the graph will SHIFT?
Up 5/4 None
Down 5/4

Verify with grapher
Linear Part 3
 y = mx + b

Enter m = 1, b = 0   
gives y = 1x + 0  or y = x
m = slope      b = y intercept  i.e.
(0, b)

Click Graph, then Click Store.
Use this graph to compare 
  • Increases means the line rises from left to right (positive slope)
  • Decreases means the line falls from left to right (negative slope)

1 . Enter m = 2/3 b = 0 

Predict which way the graph will CHANGE?
Increases - gets steeper  None
Increases - gets flatter
Decreases - gets steeper
Decreases - gets flatter
Now click Graph.

2. Enter m = 2, b = 0 

Predict which way the graph will CHANGE?
Increases - gets steeper  None
Increases - gets flatter
Decreases - gets steeper
Decreases - gets flatter
Now click Graph.

3. Enter m = -8, b = 0 

Predict which way the graph will CHANGE?
Increases - gets steeper None
Increases - gets flatter
Decreases - gets steeper
Decreases - gets flatter
Now click Graph.

4. Enter m = 1/10, b = 0 

Predict which way the graph will CHANGE?
Increases - gets steeper None
Increases - gets flatter
Decreases - gets steeper
Decreases - gets flatter
Now click Graph.

5. Enter m = 0, b = 0 (try b=1,-2, 1/2)

Predict which way the graph will CHANGE?
Increases - gets steeper Neither
Increases - gets flatter
Decreases - gets steeper
Decreases - gets flatter
Now click Graph.
Lines Altogether
Predict the following shifting, then verify using grapher.
y = 2x - 3
y = -2x - 4
y = (1/4) + 1
y =  2 (HINT: m = 0)
y = 25x =3