Content deleted Content added
Stuff |
→What is algebra?: reword per purgies request part 1 |
||
Line 8:
The most simple parts of algebra begin with computations similar to those of [[arithmetic]] but with variables standing for numbers.<ref name=citeboyer /> This allowed proofs of properties that are true no matter which numbers are involved. For example, in the [[quadratic equation]]
:<math>ax^2+bx+c=0,</math>
where <math>a, b, c</math>
Because algebra is simply the manipulation of entities, there is no rule that states that only numbers and variables that stand for numbers are allowed. In this way, algebra is extended to consider entities that do not stand for just one number, such as [[vector (mathematics)|vectors]], [[matrix (mathematics)|matrices]], and [[polynomial]]s. Many of these and the previously mentioned manipulation of variables form the basis of high school algebra, while others form subjects such as [[linear algebra]].
Line 14:
Even though algebra had already expanded into manipulations of many numbers in the defined topics above, it is possible to define entities that are unlike any familiar numbers. These entities are created using only their properties, and involve strict definitions that create a set of entities that work together with their properties. The entities form [[algebraic structure]]s such as [[group (mathematics)|groups]], [[ring (mathematics)|rings]], and [[field (mathematics)|fields]]. Abstract algebra is the study of these entities and more.<ref>http://abstract.ups.edu/download/aata-20150812.pdf Retrieved October 24 2018</ref>
Today,
▲Today, algebra has grown until it includes many branches of mathematics, as can be seen in the [[Mathematics Subject Classification]]<ref>{{cite web|url=http://www.ams.org/mathscinet/msc/msc2010.html|title=2010 Mathematics Subject Classification|publisher=|accessdate=5 October 2014}}</ref> where none of the first level areas (two digit entries) is called ''algebra''. Today algebra includes section 08-General algebraic systems, 12-[[Field theory (mathematics)|Field theory]] and [[polynomial]]s, 13-[[Commutative algebra]], 15-[[Linear algebra|Linear]] and [[multilinear algebra]]; [[matrix theory]], 16-[[associative algebra|Associative rings and algebras]], 17-[[Nonassociative ring]]s and [[Non-associative algebra|algebra]]s, 18-[[Category theory]]; [[homological algebra]], 19-[[K-theory]] and 20-[[Group theory]]. Algebra is also used extensively in 11-[[Number theory]] and 14-[[Algebraic geometry]].
{{collapse bottom}}
{{collapse top|Antiassociative algebra}}
==Antiassociative algebra==
An algebra antiassociative if (xy)z = -x(yz) for every case of x,y, and z.<ref>https://books.google.com/books?id=_PEWt18egGgC&pg=PA235&lpg=PA235&dq=%22antiassociative%22+algebra+aplications&source=bl&ots=Atxm0cdUVs&sig=OQjjF3ig6NYCQwP6O9P8fLgwSDE&hl=en&sa=X&ved=2ahUKEwix94P66LPdAhVIu1MKHckzBNQQ6AEwCHoECAYQAQ#v=onepage&q=%22antiassociative%22%20algebra%20aplications&f=false</ref>
|