<< Chapter < Page Chapter >> Page >

Access the following online resource for additional instruction and practice with graphing polynomial functions.

Key concepts

  • Polynomial functions of degree 2 or more are smooth, continuous functions. See [link] .
  • To find the zeros of a polynomial function, if it can be factored, factor the function and set each factor equal to zero. See [link] , [link] , and [link] .
  • Another way to find the x - intercepts of a polynomial function is to graph the function and identify the points at which the graph crosses the x - axis. See [link] .
  • The multiplicity of a zero determines how the graph behaves at the x - intercepts. See [link] .
  • The graph of a polynomial will cross the horizontal axis at a zero with odd multiplicity.
  • The graph of a polynomial will touch the horizontal axis at a zero with even multiplicity.
  • The end behavior of a polynomial function depends on the leading term.
  • The graph of a polynomial function changes direction at its turning points.
  • A polynomial function of degree n has at most n 1 turning points. See [link] .
  • To graph polynomial functions, find the zeros and their multiplicities, determine the end behavior, and ensure that the final graph has at most n 1 turning points. See [link] and [link] .
  • Graphing a polynomial function helps to estimate local and global extremas. See [link] .
  • The Intermediate Value Theorem tells us that if f ( a )   and   f ( b ) have opposite signs, then there exists at least one value c between a and b for which f ( c ) = 0. See [link] .

Section exercises

Verbal

What is the difference between an x - intercept and a zero of a polynomial function f ?

The x - intercept is where the graph of the function crosses the x - axis, and the zero of the function is the input value for which f ( x ) = 0.

Got questions? Get instant answers now!

If a polynomial function of degree n has n distinct zeros, what do you know about the graph of the function?

Got questions? Get instant answers now!

Explain how the Intermediate Value Theorem can assist us in finding a zero of a function.

If we evaluate the function at a and at b and the sign of the function value changes, then we know a zero exists between a and b .

Got questions? Get instant answers now!

Explain how the factored form of the polynomial helps us in graphing it.

Got questions? Get instant answers now!

If the graph of a polynomial just touches the x -axis and then changes direction, what can we conclude about the factored form of the polynomial?

There will be a factor raised to an even power.

Got questions? Get instant answers now!

Algebraic

For the following exercises, find the x - or t -intercepts of the polynomial functions.

C ( t ) = 2 ( t 4 ) ( t + 1 ) ( t 6 )

Got questions? Get instant answers now!

C ( t ) = 3 ( t + 2 ) ( t 3 ) ( t + 5 )

( 2 , 0 ) , ( 3 , 0 ) , ( 5 , 0 )

Got questions? Get instant answers now!

C ( t ) = 4 t ( t 2 ) 2 ( t + 1 )

Got questions? Get instant answers now!

C ( t ) = 2 t ( t 3 ) ( t + 1 ) 2

( 3 , 0 ) , ( 1 , 0 ) , ( 0 , 0 )

Got questions? Get instant answers now!

C ( t ) = 2 t 4 8 t 3 + 6 t 2

Got questions? Get instant answers now!

C ( t ) = 4 t 4 + 12 t 3 40 t 2

( 0 , 0 ) ,   ( 5 , 0 ) ,   ( 2 , 0 )

Got questions? Get instant answers now!

f ( x ) = x 4 x 2

Got questions? Get instant answers now!

f ( x ) = x 3 + x 2 20 x

( 0 , 0 ) ,   ( 5 , 0 ) ,   ( 4 , 0 )

Got questions? Get instant answers now!

f ( x ) = x 3 + 6 x 2 7 x

Got questions? Get instant answers now!

f ( x ) = x 3 + x 2 4 x 4

( 2 , 0 ) ,   ( 2 , 0 ) ,   ( 1 , 0 )

Got questions? Get instant answers now!

f ( x ) = x 3 + 2 x 2 9 x 18

Got questions? Get instant answers now!

f ( x ) = 2 x 3 x 2 8 x + 4

( 2 , 0 ) , ( 2 , 0 ) , ( 1 2 , 0 )

Got questions? Get instant answers now!

f ( x ) = x 6 7 x 3 8

Got questions? Get instant answers now!

f ( x ) = 2 x 4 + 6 x 2 8

( 1 , 0 ) ,   ( 1 , 0 )

Got questions? Get instant answers now!

f ( x ) = x 3 3 x 2 x + 3

Got questions? Get instant answers now!

f ( x ) = x 6 2 x 4 3 x 2

( 0 , 0 ) , ( 3 , 0 ) , ( 3 , 0 )

Got questions? Get instant answers now!

f ( x ) = x 6 3 x 4 4 x 2

Got questions? Get instant answers now!

f ( x ) = x 5 5 x 3 + 4 x

( 0 , 0 ) ,   ( 1 , 0 ) ( 1 , 0 ) ,   ( 2 , 0 ) ,   ( 2 , 0 )

Got questions? Get instant answers now!

For the following exercises, use the Intermediate Value Theorem to confirm that the given polynomial has at least one zero within the given interval.

f ( x ) = x 3 9 x , between x = −4 and x = −2.

Got questions? Get instant answers now!

f ( x ) = x 3 9 x , between x = 2 and x = 4.

f ( 2 ) = 10 and f ( 4 ) = 28. Sign change confirms.

Got questions? Get instant answers now!

Questions & Answers

how did you get 1640
Noor Reply
If auger is pair are the roots of equation x2+5x-3=0
Peter Reply
Wayne and Dennis like to ride the bike path from Riverside Park to the beach. Dennis’s speed is seven miles per hour faster than Wayne’s speed, so it takes Wayne 2 hours to ride to the beach while it takes Dennis 1.5 hours for the ride. Find the speed of both bikers.
MATTHEW Reply
420
Sharon
from theory: distance [miles] = speed [mph] × time [hours] info #1 speed_Dennis × 1.5 = speed_Wayne × 2 => speed_Wayne = 0.75 × speed_Dennis (i) info #2 speed_Dennis = speed_Wayne + 7 [mph] (ii) use (i) in (ii) => [...] speed_Dennis = 28 mph speed_Wayne = 21 mph
George
Let W be Wayne's speed in miles per hour and D be Dennis's speed in miles per hour. We know that W + 7 = D and W * 2 = D * 1.5. Substituting the first equation into the second: W * 2 = (W + 7) * 1.5 W * 2 = W * 1.5 + 7 * 1.5 0.5 * W = 7 * 1.5 W = 7 * 3 or 21 W is 21 D = W + 7 D = 21 + 7 D = 28
Salma
Devon is 32 32​​ years older than his son, Milan. The sum of both their ages is 54 54​. Using the variables d d​ and m m​ to represent the ages of Devon and Milan, respectively, write a system of equations to describe this situation. Enter the equations below, separated by a comma.
Aaron Reply
find product (-6m+6) ( 3m²+4m-3)
SIMRAN Reply
-42m²+60m-18
Salma
what is the solution
bill
how did you arrive at this answer?
bill
-24m+3+3mÁ^2
Susan
i really want to learn
Amira
I only got 42 the rest i don't know how to solve it. Please i need help from anyone to help me improve my solving mathematics please
Amira
Hw did u arrive to this answer.
Aphelele
hi
Bajemah
-6m(3mA²+4m-3)+6(3mA²+4m-3) =-18m²A²-24m²+18m+18mA²+24m-18 Rearrange like items -18m²A²-24m²+42m+18A²-18
Salma
complete the table of valuesfor each given equatio then graph. 1.x+2y=3
Jovelyn Reply
x=3-2y
Salma
y=x+3/2
Salma
Hi
Enock
given that (7x-5):(2+4x)=8:7find the value of x
Nandala
3x-12y=18
Kelvin
please why isn't that the 0is in ten thousand place
Grace Reply
please why is it that the 0is in the place of ten thousand
Grace
Send the example to me here and let me see
Stephen
A meditation garden is in the shape of a right triangle, with one leg 7 feet. The length of the hypotenuse is one more than the length of one of the other legs. Find the lengths of the hypotenuse and the other leg
Marry Reply
how far
Abubakar
cool u
Enock
state in which quadrant or on which axis each of the following angles given measure. in standard position would lie 89°
Abegail Reply
hello
BenJay
hi
Method
I am eliacin, I need your help in maths
Rood
how can I help
Sir
hmm can we speak here?
Amoon
however, may I ask you some questions about Algarba?
Amoon
hi
Enock
what the last part of the problem mean?
Roger
The Jones family took a 15 mile canoe ride down the Indian River in three hours. After lunch, the return trip back up the river took five hours. Find the rate, in mph, of the canoe in still water and the rate of the current.
cameron Reply
Shakir works at a computer store. His weekly pay will be either a fixed amount, $925, or $500 plus 12% of his total sales. How much should his total sales be for his variable pay option to exceed the fixed amount of $925.
mahnoor Reply
I'm guessing, but it's somewhere around $4335.00 I think
Lewis
12% of sales will need to exceed 925 - 500, or 425 to exceed fixed amount option. What amount of sales does that equal? 425 ÷ (12÷100) = 3541.67. So the answer is sales greater than 3541.67. Check: Sales = 3542 Commission 12%=425.04 Pay = 500 + 425.04 = 925.04. 925.04 > 925.00
Munster
difference between rational and irrational numbers
Arundhati Reply
When traveling to Great Britain, Bethany exchanged $602 US dollars into £515 British pounds. How many pounds did she receive for each US dollar?
Jakoiya Reply
how to reduced echelon form
Solomon Reply
Jazmine trained for 3 hours on Saturday. She ran 8 miles and then biked 24 miles. Her biking speed is 4 mph faster than her running speed. What is her running speed?
Zack Reply
d=r×t the equation would be 8/r+24/r+4=3 worked out
Sheirtina
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply
Practice Key Terms 4

Get Jobilize Job Search Mobile App in your pocket Now!

Get it on Google Play Download on the App Store Now




Source:  OpenStax, Algebra and trigonometry. OpenStax CNX. Nov 14, 2016 Download for free at https://legacy.cnx.org/content/col11758/1.6
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Algebra and trigonometry' conversation and receive update notifications?

Ask