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2.6 transformations

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Page 1: 2.6 transformations
Page 2: 2.6 transformations

• When we make a new function based on an

old one, we call it a function

transformation• Come in four basic categories:

• Translations (shifting/sliding)

• Dilations (shrinking or stretching)

• Rotations

• Reflections

• For now, we will study only

translations and dilations.

Page 3: 2.6 transformations

We can use function notation to build

new functions:

Example 1:

The outputs for k are the same as for f

except we add 3 to them

Example 2:

The outputs for k are 2 times the

outputs for f

( ) ( ) 3k x f x

( ) 2 ( )k x f x

Page 4: 2.6 transformations

Here’s the definition of f(x):

I want to make a new function

What does the table look like?

x 0 1 2 3 4

f(x) 8 7 9 -2 5

x 0 1 2 3 4

k(x) 11 10 12 1 8

( ) ( ) 3k x f x

Page 5: 2.6 transformations

x 0 1 2 3 4

f(x) 8 7 9 -2 5

x 0 1 2 3 4

f(x)-7

x 0 1 2 3 4

f(x)+10

Use this function definition to complete the definitions below:

Page 6: 2.6 transformations

x 0 1 2 3 4

g(x) 12 9 -4 0 -1

x 0 1 2 3 4

g(x) – 3

Use this function definition to complete the definition below:

Page 7: 2.6 transformations

Here’s the

definition of f(x):

I want to make a

new function

What does the

graph look like?

( ) ( ) 2k x f x

Page 8: 2.6 transformations

Here’s the definition

of f(x):

I want to make a

new function

( ) ( ) 1k x f x

Page 9: 2.6 transformations

Use the same

definition of f(x)

from the example:

Draw a graph for

the new function

Page 10: 2.6 transformations

Vertical shifts added/subtracted

something to the output values.

Horizontal shifts will add/subtract

something to the input values.

Example: h(x) = f(x + 1)

is a horizontal shift.

Page 11: 2.6 transformations

When the input is changed, we need

to “undo” that change to see what

happens to the graph/table.

So, f(x + 1) means we subtract 1

from the x values.

And, f(x – 1) means we add 1 to the x

values.

Page 12: 2.6 transformations

Output values stay the same!

Add/subtract (do the opposite!) to change

the input values.

Example:

Make a table for the new function

x 0 1 2 3 4

f(x) 8 7 9 -2 5

( ) ( 1)k x f x

x

k(x)

Page 13: 2.6 transformations

Make a table for the new function

x 0 1 2 3 4

f(x) 8 7 9 -2 5

x

g(x)

Page 14: 2.6 transformations

Remember we “undo” the change to

the input, so:

(x - #) means add shift right

(x + #) means subtract shift left

Page 15: 2.6 transformations

Here is f(x).

Sketch:

Page 16: 2.6 transformations

Here is f(x).

Sketch:

Page 17: 2.6 transformations

Dilations occur when a function is

multiplied by a number.

Vertical dilations – outputs multiplied

◦ 2f(x)

Horizontal dilations – inputs multiplied

◦ f(2x)

(We will only do vertical stretches/shrinks.)

Page 18: 2.6 transformations

Make a table for the new function

x 0 1 2 3 4

f(x) 8 7 9 -2 5

x

g(x)

Page 19: 2.6 transformations

Make a table for the new function

x 0 1 2 3 4

f(x) 8 7 9 -2 5

x

h(x)

Page 20: 2.6 transformations

Here is f(x).

Sketch:

Page 21: 2.6 transformations

Here is f(x).

Sketch: