Transformation of Graphs

 

Graph of y=|f(x)|

 

y={f(x),f(x)0f(x),f(x)<0

 

Graph of y=|f(x)| based on given y=f(x):

  • part of the graph above x-axis does not change
  • part of the graph below x-axis reflected about the x-axis

 

y=f(x)

 

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y=|f(x)|

 

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Graph of y=f(|x|)

 

f(|x|)={f(x),x0f(x),x<0

 

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Graph of y=1f(x)

 

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y=f(x) y=1f(x)
For f(x)=0

is that the x-intercept

y=1f(x) does not exist

x-intercept of y=f(x) becomes the vertical asymtotes

Vertical asymtotes of f(x) Vertical asymtotes of y=f(x) becomes x-intercept,

but does not touch x-axis (indicate by hollow circles)

Maximum point at (x,f(x)) Maximum point of y=f(x) becomes minimum point at (x,1f(x))
Minimum point at (x,f(x)) Minimum point of y=f(x) becomes maximum point at (x,1f(x))
When f(x)=1 1f(x)=1

common point

When f(x)=1 1f(x)=1

common point

When f(x)>0 1f(x)>0
When f(x)<0 1f(x)<0
When f(x) increases 1f(x) decreases
When f(x) decreases 1f(x) increases

 


Graph of y2=f(x)

 

Graph of y2=f(x) based on given y=f(x):

  • y2=f(x)y=±f(x)
  • sketch the graph of y=f(x) based on y=f(x)
  • sketch the graph of y=f(x) as a reflection of y=f(x)

 

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y=f(x) y=f(x)
For f(x)<0 f(x) is not defined, no graph
For any point (h,k) where k>0 The point will become (h,k)
Horizontal asymptote y=c Horizontal asymtote will become y=c
Vertical asymptote x=a Vertical asymptote x=a, no change
When f(x)=0 f(x)=0
When f(x)=1 f(x)=1
When 0<f(x)<1 f(x)>f(x), that means the graph will be higher
When f(x)>1 f(x)<f(x), that means the graph will be lower
Exercise

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Graphs (Prev Lesson)

Rational Functions and Graphs