Functions Test!

Quick recap• Each question will appear for 20s and you

must try to answer as many as you can…A translation of 5 units in the x direction means that you replace…

f(x)-5 represents what transformation?

y=(2x)2 represents what transformation of y=x2

What two transformations change y=3x+1 into y=-3x+2?

Why must you be careful if translating and stretching in the x direction?

x with x-5

Translation 5 units down in y or -5 units in y

Stretch scale factor 1/2 in the x direction

Reflect in the x axis followed by translation of 1 unit in y

The order matters and gives a different image.

Combined Transformations

• Know when order combined transformations is important

• Understand how to perform a combination of transformations where the same variable is replaced.

• Be able to show these combinations of transformations in function notation. How you can find out what pairs of transformations cause a function to change into another.

Notation

• You need to be able to interrupt combined transformations with function notations.

baxf )(

b

a

)(axbf axis- // x s.f.stretch a1

axis-y // b s.f.stretch

Notation

• You need to be able to interrupt combined transformations with function notations.

)204( xf

0

5

axis- // x s.f.stretch 41

))5(4( xf

Notation

• You need to be able to interrupt combined transformations with function notations.

6)(2 xf

3

0

axis-y // 2 s.f.stretch 3)(2 xf

Dominoes time!

The order of combinations

When doing combined transformations on the x and y variable, the order doesn’t matter.

BUT if you do two transformations on the same variable, the order does matter!

Backwards

You will need to be able to find transformations if given an image and what it was mapped from.

e.g. What two transformations maps

22 12 xx

0

1axis- // x1/2 SFstretch

21x 212 x

Backwards

You will need to be able to find transformations if given an image and what it was mapped from.

0

1axis- // x1/2 SFstretch

22x 212 x

222 x

Have a go at Exam Qs

Independent Study

Exercise C p49 (solution p169)