<< Chapter < Page Chapter >> Page >

Inleiding

In hierdie hoofstuk sal jy leer van 'n eenvoudiger manier om uitdrukkings soos 2 × 2 × 2 × 2 te skryf. Dit staan bekend as eksponensiaalnotasie .

Definisie

Eksponensiaalnotasie is 'n kort manier om te skryf dat 'n getal meermale met homself vermenigvuldig word. Byvoorbeeld, eerder as om te skryf 5 × 5 × 5 , gebruik ons 5 3 om aan te dui dat die getal 5 drie maal met homself vermenigvuldig word en 'n mens sê "5 tot die mag 3". Soortgelyk is 5 2 dieselfde as 5 × 5 en 3 5 is 3 × 3 × 3 × 3 × 3 . Laat ons beter definieer hoe om eksponensiaalnotasie te gebruik.

Eksponensiaalnotasie

Eksponensiaalnotasie verwys na 'n getal wat geskryf word as

a n

waar n 'n heelgetal is en a enige reële getal is. Ons noem a die grondtal en n die eksponent .

a tot die mag n is

a n = a × a × × a ( n -keer )

Dit wil sê, a word n keer met homself vermenigvuldig.

Ons kan ook 'n negatiewe eksponent, - n , gebruik. In hierdie geval

a - n = 1 a × a × × a ( n -keer )
Eksponente

Indien n 'n ewe getal is, sal a n altyd 'n positiewe getal wees vir enige reële getal a , behalwe 0 . Byvoorbeeld, hoewel - 2 negatief is, is beide ( - 2 ) 2 = - 2 × - 2 = 4 en ( - 2 ) - 2 = 1 - 2 × - 2 = 1 4 positief.

Khan academy video oor eksponente 1 (in engels)

Khan academy video oor eksponente 2 (in engels)

Eksponentwette

Daar is heelwat eksponentwette wat ons kan gebruik om getalle met eksponente te vereenvoudig. Sommige van hierdie wette het ons reeds in vorige grade teëgekom, maar ons sal die volledige lys hier sien en elke wet verduidelik, sodat jy hulle kan verstaan en nie bloot memoriseer nie.

a 0 = 1 a m × a n = a m + n a - n = 1 a n a m ÷ a n = a m - n ( a b ) n = a n b n ( a m ) n = a m n

Eksponente, wet 1: a 0 = 1

Volgens die definisie van eksponensiaalnotasie is

a 0 = 1 , ( a 0 )

Byvoorbeeld, x 0 = 1 en ( 1 000 000 ) 0 = 1

Toepassing van wet 1: a 0 = 1 , ( a 0 )

  1. 16 0
  2. 16 a 0
  3. ( 16 + a ) 0
  4. ( - 16 ) 0
  5. - 16 0

Eksponente, wet 2: a m × a n = a m + n

Khan academy video oor eksponente 3 (in engels)

Die definisie van eksponensiaalnotasie wys dat

a m × a n = 1 × a × ... × a ( m -keer ) × 1 × a × ... × a ( n -keer ) = 1 × a × ... × a ( m + n -keer ) = a m + n

Byvoorbeeld,

2 7 × 2 3 = ( 2 × 2 × 2 × 2 × 2 × 2 × 2 ) × ( 2 × 2 × 2 ) = 2 7 + 3 = 2 10

Interessante feit

Hierdie eenvoudige wet is die rede waarom eksponente oorspronklik geskep is. Voor die dae van rekenaars moes vermenigvuldiging met potlood en papier gedoen word. Dit vat baie lank om vermenigvuldiging te doen, maar dit is vinnig en eenvoudig om getalle bymekaar te tel. Hierdie eksponentwet wys dat dit moontlik is om twee getalle te vermenigvuldig deur hulle eksponente bymekaar te tel (indien hulle dieselfde grondtal het). Hierdie ontdekking het wiskundiges baie tyd gespaar, wat hulle toe kon gebruik om iets meer produktiefs te doen.

Toepassing van wet 2: a m × a n = a m + n

  1. x 2 · x 5
  2. 2 3 . 2 4 [Neem kennis dat die grondtal (2) dieselfde bly.]
  3. 3 × 3 2 a × 3 2

Eksponente, wet 3: a - n = 1 a n , a 0

Die definisie van eksponensiaalnotasie vir 'n negatiewe eksponent wys dat

a - n = 1 ÷ a ÷ ... ÷ a ( n -keer ) = 1 1 × a × × a ( n -keer ) = 1 a n

Dit beteken dat 'n minus teken in die eksponent 'n alternatiewe manier is om aan te dui dat die hele eksponensiaal gedeel eerder asvermenigvuldig moet word.

Byvoorbeeld,

2 - 7 = 1 2 × 2 × 2 × 2 × 2 × 2 × 2 = 1 2 7

Toepassing van wet 3: a - n = 1 a n , a 0

  1. 2 - 2 = 1 2 2
  2. 2 - 2 3 2
  3. ( 2 3 ) - 3
  4. m n - 4
  5. a - 3 · x 4 a 5 · x - 2

Eksponente, wet 4: a m ÷ a n = a m - n

Met Wet 3 het ons reeds besef dat 'n minusteken 'n manier is om te wys dat die eksponensiaal gedeel eerder as vermenigvuldig moetword. Wet 4 is basies 'n meer algemene manier om dieselfde stelling te maak. Ons verkry hierdie wet deur Wet 3 aan beide kante met a m te vermenigvuldig en dan Wet 2 te gebruik.

a m a n = a m a - n = a m - n

Byvoorbeeld,

2 7 ÷ 2 3 = 2 × 2 × 2 × 2 × 2 × 2 × 2 2 × 2 × 2 = 2 × 2 × 2 × 2 = 2 4 = 2 7 - 3

Khan academy video oor eksponente 4 (in engels)

Toepassing van wet 4: a m ÷ a n = a m - n

  1. a 6 a 2 = a 6 - 2
  2. 3 2 3 6
  3. 32 a 2 4 a 8
  4. a 3 x a 4

Eksponente, wet 5: ( a b ) n = a n b n

Die volgorde waarin twee getalle vermenigvuldig word, is onbelangrik. Dus,

( a b ) n = a × b × a × b × ... × a × b ( n -keer ) = a × a × ... × a ( n -keer ) × b × b × ... × b ( n -keer ) = a n b n

Byvoorbeeld,

( 2 · 3 ) 4 = ( 2 · 3 ) × ( 2 · 3 ) × ( 2 · 3 ) × ( 2 · 3 ) = ( 2 × 2 × 2 × 2 ) × ( 3 × 3 × 3 × 3 ) = ( 2 4 ) × ( 3 4 ) = 2 4 3 4

Toepassing van wet 5: ( a b ) n = a n b n

  1. ( 2 x y ) 3 = 2 3 x 3 y 3
  2. ( 7 a b ) 2
  3. ( 5 a ) 3

Eksponente, wet 6: ( a m ) n = a m n

Dit is moontlik om die eksponensiaal van 'n eksponensiaal te bereken. Die eksponensiaal van 'n getal is 'n reële getal. So, selfs al klink die eerste sin ingewikkeld, beteken dit bloot dat 'n mens die eksponensiaal van 'n getal bereken en dan die eksponensiaal van die resultaat bereken.

( a m ) n = a m × a m × ... × a m ( n -keer ) = a × a × ... × a ( m × n -keer ) = a m n

Byvoorbeeld,

( 2 2 ) 3 = ( 2 2 ) × ( 2 2 ) × ( 2 2 ) = ( 2 × 2 ) × ( 2 × 2 ) × ( 2 × 2 ) = ( 2 6 ) = 2 ( 2 × 3 )

Toepassing van wet 6: ( a m ) n = a m n

  1. ( x 3 ) 4
  2. [ ( a 4 ) 3 ] 2
  3. ( 3 n + 3 ) 2

Vereenvoudig: 5 2 x - 1 · 9 x - 2 15 2 x - 3

  1. = 5 2 x - 1 · ( 3 2 ) x - 2 ( 5 . 3 ) 2 x - 3 = 5 2 x - 1 · 3 2 x - 4 5 2 x - 3 · 3 2 x - 3
  2. = 5 2 x - 1 - 2 x + 3 · 3 2 x - 4 - 2 x + 3 = 5 2 · 3 - 1
  3. = 25 3

Ondersoek: eksponensiale

Skryf die korrekte antwoord in the Antwoord kolom. Die beskikbare antwoorde is: 3 2 , 1, - 1 , - 1 3 , 8. Antwoorde mag herhaal word.

Vraag Antwoord
2 3
7 3 - 3
( 2 3 ) - 1
8 7 - 6
( - 3 ) - 1
( - 1 ) 23

Die volgende video gee 'n voorbeeld van hoe om sommige van die konsepte wat in hierdie hoofstuk gedek is, te gebruik.

Khan academy video oor eksponente 5 (in engels)

Hoofstukoefeninge

  1. Vereenvoudig so ver as moontlik.
    1. 302 0
    2. 1 0
    3. ( x y z ) 0
    4. [ ( 3 x 4 y 7 z 12 ) 5 ( - 5 x 9 y 3 z 4 ) 2 ] 0
    5. ( 2 x ) 3
    6. ( - 2 x ) 3
    7. ( 2 x ) 4
    8. ( - 2 x ) 4

  2. Vereenvoudig sonder om 'n sakrekenaar te gebruik. Skryf antwoorde met positiewe eksponente.
    1. 3 x - 3 ( 3 x ) 2
    2. 5 x 0 + 8 - 2 - ( 1 2 ) - 2 · 1 x
    3. 5 b - 3 5 b + 1

  3. Vereenvoudig en wys alle stappe.
    1. 2 a - 2 . 3 a + 3 6 a
    2. a 2 m + n + p a m + n + p · a m
    3. 3 n · 9 n - 3 27 n - 1
    4. ( 2 x 2 a y - b ) 3
    5. 2 3 x - 1 · 8 x + 1 4 2 x - 2
    6. 6 2 x · 11 2 x 22 2 x - 1 · 3 2 x

  4. Vereenvoudig sonder om 'n sakrekenaar te gebruik.
    1. ( - 3 ) - 3 · ( - 3 ) 2 ( - 3 ) - 4
    2. ( 3 - 1 + 2 - 1 ) - 1
    3. 9 n - 1 · 27 3 - 2 n 81 2 - n
    4. 2 3 n + 2 · 8 n - 3 4 3 n - 2

Questions & Answers

what is homeostasis?
Samuel Reply
what's physiology
AminchiSunday Reply
what is physiology
AminchiSunday
physically is the study of the function of the body
Najaatu
that is what I want ask
YAU
u are wright
YAU
pls what are the main treatment of hiccups
YAU
physiology is the study of the function of the body
Najaatu
hiccups happen when something irritates the nerves that course your diaphragm to contract
Najaatu
how did hypothalamus manege to control all activities of the various hormones
malual
how can I treat pain a patient feels after eating meals
Namuli Reply
how do I treat a three year old baby of skin infection?
Okocha Reply
It depends on the type of infection. Bacterial, fungal, parasitic or viral?
schler
if you can share the sign ad symptoms of the skin infection then u geh the treatment cox they're different sign ad symptoms of skin infection with different treatment
Sa
prostaglandin and fever
Maha Reply
yes
rayyanu
welcome sir
rayyanu
prostaglandin E2 is the final mediator.
Lemlem
prostaglandin E2 is the final mediator of fever.
Lemlem
yes
Agabi
good evening
Jediel
Discuss the differences between taste and flavor, including how other sensory inputs contribute to our  perception of flavor.
John Reply
taste refers to your understanding of the flavor . while flavor one The other hand is refers to sort of just a blend things.
Faith
While taste primarily relies on our taste buds, flavor involves a complex interplay between taste and aroma
Kamara
which drugs can we use for ulcers
Ummi Reply
omeprazole
Kamara
what
Renee
what is this
Renee
is a drug
Kamara
of anti-ulcer
Kamara
Omeprazole Cimetidine / Tagament For the complicated once ulcer - kit
Patrick
what is the function of lymphatic system
Nency Reply
Not really sure
Eli
to drain extracellular fluid all over the body.
asegid
The lymphatic system plays several crucial roles in the human body, functioning as a key component of the immune system and contributing to the maintenance of fluid balance. Its main functions include: 1. Immune Response: The lymphatic system produces and transports lymphocytes, which are a type of
asegid
to transport fluids fats proteins and lymphocytes to the blood stream as lymph
Adama
what is anatomy
Oyindarmola Reply
Anatomy is the identification and description of the structures of living things
Kamara
what's the difference between anatomy and physiology
Oyerinde Reply
Anatomy is the study of the structure of the body, while physiology is the study of the function of the body. Anatomy looks at the body's organs and systems, while physiology looks at how those organs and systems work together to keep the body functioning.
AI-Robot
what is enzymes all about?
Mohammed Reply
Enzymes are proteins that help speed up chemical reactions in our bodies. Enzymes are essential for digestion, liver function and much more. Too much or too little of a certain enzyme can cause health problems
Kamara
yes
Prince
how does the stomach protect itself from the damaging effects of HCl
Wulku Reply
little girl okay how does the stomach protect itself from the damaging effect of HCL
Wulku
it is because of the enzyme that the stomach produce that help the stomach from the damaging effect of HCL
Kamara
function of digestive system
Ali Reply
function of digestive
Ali
the diagram of the lungs
Adaeze Reply
what is the normal body temperature
Diya Reply
37 degrees selcius
Xolo
37°c
Stephanie
please why 37 degree selcius normal temperature
Mark
36.5
Simon
37°c
Iyogho
the normal temperature is 37°c or 98.6 °Fahrenheit is important for maintaining the homeostasis in the body the body regular this temperature through the process called thermoregulation which involves brain skin muscle and other organ working together to maintain stable internal temperature
Stephanie
37A c
Wulku
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get Jobilize Job Search Mobile App in your pocket Now!

Get it on Google Play Download on the App Store Now




Source:  OpenStax, Siyavula textbooks: wiskunde (graad 10) [caps]. OpenStax CNX. Aug 04, 2011 Download for free at http://cnx.org/content/col11328/1.4
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Siyavula textbooks: wiskunde (graad 10) [caps]' conversation and receive update notifications?

Ask