7.6 –Polynomial Graphs 1

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7.6 –Polynomial Graphs 1
End Behavior
We can see that the ____________ and _____________ ___________ drive the
graph of the polynomial function!
You Try!
What is the end behavior of 𝑓 π‘₯ = βˆ’3π‘₯ ! βˆ’ π‘₯ ! ?
Key Terms:
Relative (local) __________
________
__
Absolute __________
__________
Relative (local) __________
________
__
Lets look at 𝑓 π‘₯ = (π‘₯ + 1) π‘₯ βˆ’ 2
!
Absolute __________
or in Standard Form:
𝑓 π‘₯ = π‘₯ ! βˆ’ 3π‘₯ ! + 4
Graph the function. Label all extrema, zeros, intercepts and end behavior. Round to the nearest
hundredth, if necessary.
To find:
`$2
To reset viewing window:
#6
x
f(x)
`$3
`$4
7.6 –Polynomial Graphs 2
For each of the following, use the end behavior and x-intercepts to match the equation to its graph.
1.
f ( x) = x 3 βˆ’ 3 x 2
A
f ( x) = βˆ’2 x 3 + 8 x
2.
B
3.
f ( x) = βˆ’2( x + 3) 2 ( x + 1) 2
C
More Graphing….
Graph the function. Label all extrema, zeros, intercepts and end behavior. Round to the nearest
hundredth, if necessary.
𝑓 π‘₯ = Zeros:
x
f(x)
y-intercept:
Extrema:
End Behavior:
Find all extrema, zeros, intercepts and end behavior. Round to the nearest hundredth, if necessary.
Function
𝑓 π‘₯ = 8π‘₯ ! βˆ’ 5βˆ’π‘₯ !
Degree
Leading
Coefficient
Zeros
y-Intercept
Extrema
End Behavior
7.6 –Polynomial Graphs 3
Practice 7.6
For each of the following, use the end behavior and x-intercepts to match the equation to its graph.
1. f ( x) = x
2. f ( x) = ( x βˆ’ 1)( x βˆ’ 3)( x βˆ’ 5)
3. f ( x) = βˆ’ x 3 + 9 x
4. f ( x) = βˆ’3( x βˆ’ 1)( x βˆ’ 2) 2 ( x βˆ’ 3)
5. f ( x) = βˆ’2 x 2 + 16 x βˆ’ 24
6. f ( x) = 3x 4 βˆ’ 3x 3 βˆ’ 3x 2 + 3x
A
B
C
D
E
F
7. Graph the function. Label all extrema, zeros, intercepts and end behavior. Round to the nearest hundredth, if necessary.
𝑓 π‘₯ = βˆ’π‘₯ ! + 5π‘₯ ! βˆ’ π‘₯ βˆ’
!
!
x
f(x)
8. Graph the function. Label all extrema, zeros, intercepts and end behavior. Round to the nearest hundredth, if necessary.
!
!
!
!
𝑓 π‘₯ = π‘₯ ! βˆ’ π‘₯ ! βˆ’ 3π‘₯ + 2
x
f(x)
7.6 –Polynomial Graphs 4
9. Graph the function. Label all extrema, zeros, intercepts and end behavior. Round to the nearest hundredth, if necessary.
𝑓 π‘₯ = π‘₯ ! βˆ’ 6π‘₯ ! + 5π‘₯
x
f(x)
10. Graph the function in your calculator. Label all extrema, zeros, intercepts and end behavior. Round to the nearest
hundredth, if necessary.
Function
𝑓 π‘₯ = π‘₯ ! βˆ’ 8π‘₯ ! βˆ’ 12
𝑓 π‘₯ = 3π‘₯ ! βˆ’ 2π‘₯ ! + 2π‘₯
𝑓 π‘₯ = π‘₯(π‘₯ βˆ’ 20)(π‘₯ + 15)(π‘₯ βˆ’ 12)
𝑓 π‘₯ = 8 βˆ’ 2π‘₯ ! + 4π‘₯ ! βˆ’ 5π‘₯
𝑓 π‘₯ = 1 !
π‘₯ + 2π‘₯ βˆ’ 1
200
Degree
Leading
Coefficient
Zeros
y-Intercept
Extrema
End
Behavior
7.6 –Polynomial Graphs 5
Application 7.6
1. Graph the function in your calculator. Label all extrema, zeros, intercepts and end behavior. Round to the nearest hundredth,
if necessary.
Function
Degree
Leading
Coefficient
Zeros
y-Intercept
Extrema
End Behavior
𝑓 π‘₯ = π‘₯ ! + 3π‘₯ ! βˆ’ 6π‘₯ βˆ’ 6
2.
Consider f(x) where:
a.
𝒇 𝒙 = π’™πŸ’ βˆ’ πŸ–. πŸ”πŸ“π’™πŸ‘ + πŸπŸ•. πŸ‘πŸ’π’™πŸ βˆ’ πŸ‘πŸ•. πŸπŸπŸ–πŸ“π’™ + πŸπŸ–. πŸπŸ•
What are the degree, leading coefficient and end behavior of the function?
x
f(x)
-­β€4 -­β€3 -­β€2 Make a table of values for βˆ’4 ≀ π‘₯ ≀ 4. How many zeros does the function
appear to have from the table?
-­β€1 0 Now change your window to àοƒ 
1 2 3 4 Degree = ________;
b.
c.
d.
3.
Leading Coefficient = _______; End Behavior:
What conclusions can you make from this new view of the graph?
The average annual price of gasoline can be modeled by the cubic function :
𝒄 𝒕 = 𝟎. πŸŽπŸŽπŸŽπŸ•π’•πŸ‘ βˆ’ 𝟎. πŸŽπŸπŸ’π’•πŸ + 𝟎. πŸŽπŸ–π’• + 𝟎. πŸ—πŸ”
where 𝑐 𝑑 is the price in dollars and t is the number of years since 1987.
a.
Graph the function in your calculator using a domain of 0 ≀ 𝑑 ≀ 30. Sketch a picture of your graph:
b.
Describe any extrema and end behavior.
c.
This model was created in 2007. Using the model, predict the price of
gasoline in 2014. How accurate is the model?
d.
Going beyond the given domain in a model is called extrapolation. Explain why extrapolation
can be dangerous when predicting future events.
7.6 –Polynomial Graphs 6
4.
a.
Create a 5th degree polynomial that has only1 zero.
What polynomial did you create?
Polynomial____________________________________
b.
Sketch your polynomial graph to the right β†’
GRAPH
Below, the graph of 𝑓 π‘₯ = π‘₯ βˆ’ 4 ! + 4
3.
is sketched in bold. Its parent function
!
𝑓 π‘₯ = π‘₯ is represented by the thin curve.
Algebra Skillz
SIMPLIFY
βˆ’4 20 + 2 80 + 45
SOLVE
5. Solve:
3π‘₯ ! (π‘₯ + 7) 7π‘₯ βˆ’ 15 = 0
1. Describe the translation of the parent
graph.
2. How does the translation relate to the
equation?
4. βˆ’2 5 1 βˆ’ 2 5
6. Factor and solve.
π‘₯ ! βˆ’ 2π‘₯ ! + π‘₯ = 0
SAT Review
MUTIPLE CHOICE
Which of the following could be the degree of f(x)?
Free Response
Find the degree of the following polynomial.
𝑓 π‘₯ = π‘₯(π‘₯ βˆ’ 3)!
(A)
(B)
(C)
(D)
(E)
2
3
4
5
7