What does the letter y represent in algebra?

In algebra, the letter y typically represents a variable or an unknown value that can change.

In more detail, a variable is a symbol used to represent a number in mathematical expressions and equations. The letter y is commonly used alongside other letters like x, z, and t. When you see y in an equation, it means that y can take on different values depending on the context of the problem. For example, in the equation y = 2x + 3, y is dependent on the value of x. As x changes, the value of y will also change according to the relationship defined by the equation.

Variables like y are essential in algebra because they allow us to generalise mathematical relationships and solve problems involving unknown quantities. For instance, if you are given the equation y = 2x + 3 and you know the value of x, you can substitute x into the equation to find the corresponding value of y. This process is called solving for y.

In coordinate geometry, y often represents the vertical position of a point on a graph, while x represents the horizontal position. The pair (x, y) is called an ordered pair and is used to locate points on the Cartesian plane. For example, the point (3, 5) means that x is 3 and y is 5.

Understanding the role of y as a variable helps you to analyse and solve a wide range of mathematical problems, from simple equations to more complex functions and graphs.