# Algebra

part of mathematics in which letters and other symbols are used to represent numbers and quantities in formulae and equation

Algebra is one of the broad parts of mathematics, together with number theory, geometry and analysis. In its most general form, algebra is the study of mathematical symbols and the rules for manipulating these symbols; it is a unifying thread of almost all of mathematics. It includes everything from elementary equation solving to the study of abstractions such as groups, rings, and fields. The more basic parts of algebra are called elementary algebra; the more abstract parts are called abstract algebra or modern algebra. Elementary algebra is generally considered to be essential for any study of mathematics, science, or engineering, as well as such applications as medicine and economics. Abstract algebra is a major area in advanced mathematics, studied primarily by professional mathematicians. The quadratic formula expresses the solution of the degree two equation a x 2 + b x + c = 0 {\displaystyle ax^{2}+bx+c=0} in terms of its coefficients a , b , c {\displaystyle a,b,c} , where a {\displaystyle a} is not zero.

## Quotes

• Algebra is the offer made by the devil to the mathematician. The devil says: `I will give you this powerful machine, it will answer any question you like. All you need to do is give me your soul: give up geometry and you will have this marvellous machine.'
• The historical associations of the word algebra almost substantiate the sordid character of the subject. The word comes from the title of a book written by... Al Khawarizmi. In this title, al-jebr w' almuqabala, the word al-jebr meant transposing a quantity from one side of an equation to another and muqabala meant simplification of the resulting expressions. Figuratively, al-jebr meant restoring the balance of an equation... When the Moors reached Spain... algebrista... came to mean a bonesetter... and signs reading Algebrista y Sangrador (bonesetter and bloodletter) were found over Spanish barber shops. Thus it might be said that there is a good historical basis for the fact that the word algebra stirs up disagreeable thoughts.
• Morris Kline, Mathematics and the Physical World (1959), p. 69
• [T]he sciences that are expressed by numbers or by other small signs, are easily learned; and... this facility rather than its demonstrability is what has made the fortune of algebra.