U1 A2- Transformations Flashcards
Translations- what does h do
and what type of translation does this result in
Change the x value
Horizontal translation
Translations- what does k do
And what type of translation does this result in
Change the y values
Vertical translation
Translations- how do you know how the y value is affected
Determine k value by isolating for y
Translations- what are the k and h values in this equation
y=(x-5)+2
k=2
h=5
Translations- k>0, graph is a translated ______
Up
Translations- k<0, graph is translated _____
Down
Translations- how to determine the k value
Isolate for y
Translations- how to determine the h value
Always opposite of what you see in equation
Since there’s no way to isolate for x
Translations- h>0, graph is a translated ______
Right
Since that’s the direction of the positive values
Translations- h<0 graph is a translated ______
Left
Since that’s the direction of the negative values
Translations- Identify the k and h values in the expression
y-4=(x+3)
k= 4
h= -3
Steps for determining a translation
1) determine k and h values
2) associate direction (vert/hor and up/down or left/ right) with each value
Mapping rule tells you how to ____ a point/graph based on what’s _____
Transform
Occuring
Mapping rule is ____ related to the words of the transformation description
Directly
Translations- what is the mapping rule for k
(x,y) —-> (x,y + k)
Translations- what is the mapping rule for h
(x,y) —-> (x+h, y)
Reflections- you can’t just flip the graph over, you have to flip it ____ the line
About
Reflections- What are the x axis and y axis also called
x axis: y=0
y axis: x=0
Reflections: what is the mapping rule for reflecting a graph over the x axis
y —> -y
Reflections: how do you determine the new expression for reflection about the x axis
1) y —> -y
2) isolate for y
Invariant points - points that
___ ____ after a transformation occurs
Don’t change
Reflections- Which points are invariant for a reflection about the x axis
(And why)
X-intercepts
In the mapping rule, y becomes -y, but you can have -0
Reflections: what is the mapping rule for reflecting a graph over the y axis
x —-> -x
Reflections: how do you determine the new expression for reflection about the x axis
1) replace every x with (-x)
Since x —-> -x
Reflections- Which points are invariant for a reflection about the y axis
(And why)
y-intercepts
In the mapping rule, x becomes -x, but you can have -0
Reflection: reflecting over the x axis is a _____ reflection (direction )
Vertical
Reflection: reflecting over the y axis is a _____ reflection (direction )
Horizontal
Stretches: in a vertical stretch what variable changes
y
Stretches: how to determine the vertical stretch factor
Isolate for y
Stretches: what is the mapping rule for a vertical stretch factor
(x,y)—-> (x, ay)
Stretches: how to determine the horizontal stretch factor
Take the reciprocal
b) —-> (1/b
Stretches: what is the mapping rule for a horizontal stretch factor
(x,y)——> (1/b x, y)
How to get a table of values from graph in calc
1) hit 2nd
2) hit graph
3) hit table
Stretches: what are the invariant points for a vertical stretch
(And why)
X-intercepts
You can multiply any stretch factor by 0 and still get 0
REMEMBER HOW YOU DESCRIBE THE TRANSFORMATION IN WORDS SHOULD BE DIRECTLY HOW THE _____ ____ IS WRITTEN
Mapping rule
Stretches: what is the vertical stretch factor in this
y—-> 5y
(1/5)
Have to divide both sides by 5 (to isolate for y)
Stretches: what variable does a horizontal stretch change
x