Why are 'x' & 'y' normally used when doing algebra?

Flynn_17

They are the names given to the axes on a graph. There's probably no relation, but when calculating simultaneous equations, it comes in very useful. Apr 05 05, 10:05 AM

peasypod

You can call up Rene Descartes (and his fly on the ceiling) and ask him, I guess. Descartes could be said to have started a movement from geometry towards algebra, using algebraic methods to solve problems in geometry. One of these was an ancient Greek problem of Pappus of Alexandria (c. 300 AD), concerning the locus of a point that moves in such a way that it always makes fixed angles with a number of given lines. His approach to the problem was to call one length on the diagram x and another length y, and then to prove that the path of the point satisfies a quadratic equation in x and y, and is therefore a conic an ellipse, parabola or hyperbola. Thus, Descartes introduced x and y into geometry, but he did not introduce the xy-Cartesian coordinates that are named after him, they came later. Apr 05 05, 5:57 PM

quizbowler1

In algebra, x and y are used to signify the axes on a coordinate plane. They are also used as variables in an equation, which means they can be replaced with any numeral that makes sense in relation to the equation. Apr 02 06, 6:24 PM