Kommutatiewe bewerking: Verskil tussen weergawes

Content deleted Content added
RAM (besprekings | bydraes)
No edit summary
RAM (besprekings | bydraes)
No edit summary
Lyn 8:
[[as en slegs as]] ''y'' en ''z'' identies is.
 
Verder as
<!-- Moet nog vertaal word
:<math>f(y,z) = f(z,y)</math>
 
vir 'n ''spesifieke'' paar elmente ''y'' en ''z'', dan word gesê dat ''y'' en ''z'', kommuteer. Elke element kommuteer met homself en in 'n [[groep (wiskunde)|groep]] kommuteer elke element met die [[identiteit (wiskunde)|identiteit]], met sy eie [[inverse]] en met sy [[eksponent]].
 
Die bekendste voorbeelde van kommutatiewe binêre bewerkings is [[sommering]] en [[vermenigvuldiging]] van [[reële getal]]le; byvoorbeeld:
For example, multiplication of real numbers is commutative since
:<math>y z = zy</math>
for ''all'' [[real number]]s ''y'' and ''z''. On the other hand, subtraction of real numbers is noncommutative, since
:<math>y-z = z-y</math>
[[iff]] ''y'' and ''z'' are identical.
 
* 4 + 5 = 5 + 4 (sinceaangesien bothbeide [[ExpressionVergelyking (mathematics)|expressionvergelyking]]s evaluatedie toresultaat 9 lewer)
Additionally, if
* 2 × 3 = 3 × 2 (aangesien beidie vergelykings die resultaat van 6 lewer)
:<math>f(y,z) = f(z,y)</math>
for a ''particular'' pair of elements ''y'' and ''z'', then ''y'' and ''z'' are said to ''commute''. Every element commutes with itself and, in a [[group (mathematics)|group]], every element commutes with the [[identity (mathematics)|identity]], with its own [[inverse]], and with its [[exponentiation|powers]].
 
The most well-known examples of commutative binary operations are [[addition]] and [[multiplication]] of [[real number]]s; for example:
 
* 4 + 5 = 5 + 4 (since both [[Expression (mathematics)|expression]]s evaluate to 9)
* 2 × 3 = 3 × 2 (since both expressions evaluate to 6)
 
<!-- Moet nog vertaal word
Further examples of commutative binary operations include addition and multiplication of [[complex number]]s, addition of [[vector space|vectors]], and [[intersection (set theory)|intersection]] and [[union (set theory)|union]] of [[set]]s. In each case, these operations are commutative over their entire domains.