Order is important when a vertical dilation is combined with a vertical translation.
A standard function form for a vertical translation is y=f(x)+cy=f(x)+c where +c+c is an upward movement along the yy-axis.
A standard function form for a vertical dilation factor is y=kf(x)y=kf(x) where kk is the vertical dilation factor.
In order to find the order of the transformations we will try. First, lets try a vertical dilation in order to transform y=x3y=x3 to y=3x3-2y=3x3−2.
The first transformation to be applied on y=x3y=x3 will be the vertical dilation factor kk where k=3k=3.
y=y=
3x33x3
Apply the vertical dilation factor k=3k=3. Remember y=kf(x)y=kf(x).
The second transformation to be applied on y=3x3y=3x3 will be the vertical translationy=f(x)+cy=f(x)+c where c=–2c=–2.
y=y=
3x3-23x3−2
Apply the vertical translation c=–2c=–2. Remember y=f(x)+cy=f(x)+c.
The vertical dilation factor is applied first.
Question 2 of 8
2. Question
When transforming y=x3y=x3 to y=(5x-1)3y=(5x−1)3, which comes first. The horizontal dilation factor of 1515 or the horizontal translation of 11 unit to the right?
1. The horizontal dilation factor is applied first.
Order is important when a horizontal dilation is combined with a horizontal translation.
A standard function form for a horizontal translation is y=f(x+h)y=f(x+h) where +h+h is a left movement along the xx-axis.
The application of the horizontal dilationfactorfactor on a xx variable is factor=1afactor=1a and we can apply xfactorxfactor.
To find the correct order we will try one of two ways.
To go from y=x3y=x3 to y=(5x-1)3y=(5x−1)3, lets try the horizontal scale factor first.
First let’s apply the Horizontal ScaleFactor=15Factor=15.
yy
==
x3x3
Then we use xfactorxfactor where we divide xx by 1515
yy
==
(x15)3(x15)3
Simplify.
yy
==
(5x)3(5x)3
Secondly, we apply the horizontal translation of 11 unit to the right
We will use y=f(x+h)y=f(x+h) where ++h++h is moving to the left
Notice h=-1h=−1 when we move to the right
We replace xx for (x-1)(x−1) in y=(5x)3y=(5x)3.
It becomes y=(5(x-1))3y=(5(x−1))3
This clearly is incorrect as it does not matchy=(5x-1)3y=(5x−1)3. Which means the order is incorrect.
Now lets try another order.
Starting with y=x3y=x3.
First we will apply the horizontal translationhh to y=x3y=x3 where h=-1h=−1 (moving to the right by 11 unit). Now we replace xx for (x-1)(x−1) in y=x3y=x3
It simplifies to y=(x-1)3y=(x−1)3.
The second transformation to be applied will be the horizontal scale factor where factor=15factor=15.
We will apply xfactorxfactor which becomes y=(x15-1)3y=(x15−1)3 this simplifies to:
y=(5x-1)3y=(5x−1)3
Yes, this matches the original function!
Correct order: first horizontal translation then horizontal dilation
The horizontal translation is applied first.
Question 3 of 8
3. Question
When transforming y=lnxy=lnx to y=ln[4(x+5)]y=ln[4(x+5)] which comes first. The horizontal dilation factor of 1414 or the horizontal translation of 55 units to the left?
1. The horizontal dilation factor is applied first.
Order is important when a horizontal dilation is combined with a horizontal translation.
A standard function form for a horizontal translation is y=f(x+h)y=f(x+h) where +h+h is a left movement along the xx-axis.
The application of the horizontal dilationfactorfactor on a xx variable is factor=1afactor=1a and we can apply xfactorxfactor.
Lets try the order that the transformations will occur so y=lnxy=lnx can become y=ln[4(x+5)]y=ln[4(x+5)].
The first transformation to be applied to y=lnxy=lnx will be the horizontal dilationfactor=14factor=14.
y=y=
lnxlnx
We will apply xfactorxfactor, take the xx and divide by 1414.
y=y=
ln(x14)ln(x14)
Simplify
y=y=
ln4xln4x
The second transformation to be applied to y=ln4xy=ln4x will be the horizontal translationhh where h=+5h=+5 since it is moving to the left by 55 units.
y=y=
ln[4(x+5)]ln[4(x+5)]
Apply the horizontal translation h=+5h=+5. Remember y=f(x+h)y=f(x+h).
Yes, this is the correct order! It matches the original function.
The horizontal dilation is applied first.
Question 4 of 8
4. Question
When transforming y=x2y=x2 to y=(15x+3)2y=(15x+3)2 is the horizontal dilation factor of 55 or the horizontal translation of 33 units left applied first?
1. The horizontal translation is applied first.
2. The horizontal dilation factor is applied first.
Order is important is when horizontal dilation is combined with a horizontal translation. Order is also important when a vertical dilation is combined with a vertical translation
A standard function form for a vertical translation is y=f(x)+c where +c is an upward movement along the y-axis.
A standard function form for a horizontal translation is y=f(x+h) where +h is a shift to the left along the x-axis.
A standard function form for a vertical dilation factor is y=kf(x) where k is the vertical dilation factor.
The application of the horizontal dilationfactor on a x variable is factor=1a or we can apply xfactor.
The universal formula form with two translations and two dilations factors in one equation is y=kf(a(x+b))+c, where b is also h in the horizontal translation. k is the vertical dilation factor. +b is shift left. +c is shift up. Horizontal factor is 1a.
To find the correct order we will take a guess to go from y=x3 to y=8(3x-9)3+2. First we are going to factor it out.
y
=
8(3(x-3))3+2
Factor out 3 from 3x-9. Now it is in the universal formula form y=kf(a(x+b))+c.
The first transformation to be applied to y=x3 will be the horizontal dilationfactor=1a where a=3 (from universal formula).
y=
(3x)3
Apply the horizontal parameter a=3. Remember factor=1a and xfactor.
The second transformation to be applied to y=(3x)3 will be the horizontal translationh where h=-3. Simply replace x for x-3.
y=
(3(x–3))3
Apply the horizontal translation h=-3. Remember y=f(x+h).
The third transformation to be applied on y=(3(x-3))3 will be the vertical dilation factor k where k=8.
y=
8(3(x-3))3
Apply the vertical dilation factor k=8. Remember y=kf(x).
The fourth transformation to be applied on y=8(3(x-3))3 will be the vertical translationy=f(x)+c where c=+2.
y=
8(3(x-3))3+2
Apply the vertical translation c=2. Remember y=f(x)+c.
Yes, this is the correct order! It matches the original function.