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Map (mathematics)

math Maturity 7-9 Next article →

Imagine you are looking at a large world map. This map shows the Earth on a small sheet of paper. In math, a map works in a very similar way. It is a way to link one thing to another.

Function color example 3
Function color example 3

You might link a shape to a specific color. You might also link a number to a new value. This link is called a function in its general sense. Many people use the words map, mapping, or operator to mean the same thing. These terms might come from the idea of making a paper map.

How does a map work in a math problem? It connects a starting group to a target group. The starting group is called the domain. The target group is called the codomain.

Function color example 3
Function color example 3

A map can be a special kind of link. In category theory, people call these links morphisms or arrows. A morphism shows exactly where a map starts and where it ends. Some maps are called transformations if they link a group back to itself. This helps mathematicians see how things change or stay the same.

Math has a long history of naming these links. Different branches of math use different names for maps.

Function color example 3
Function color example 3

In algebra, a special map is called a homomorphism. In geometry, a map that preserves size is an isometry. People in the field of analysis use the word operator. In group theory, these links are called representations. Even the term function can have a narrow meaning. Some authors use function only for maps that use numbers. This shows how many ways we can describe these connections.

There are many specific facts about these mathematical tools. A map can be a continuous function in the study of topology. In linear algebra, a map is often a linear transformation.

Function color example 3
Function color example 3

Some people, like Serge Lang, use very specific definitions. He uses the word function only for maps that result in numbers. In the study of dynamical systems, a map shows how things evolve. These are called discrete dynamical systems. These maps help us track how a system moves through time.

Maps help us understand the patterns around us. They connect the things we know to new ideas.

Function color example 3
Function color example 3

You can think of a map as a bridge between two worlds. One world is the domain and the other is the codomain. By using maps, we can study how shapes, numbers, and systems relate. Whether it is a simple color link or a complex rule, maps are essential. They are the tools that allow mathematicians to organize the world. They turn many separate parts into one connected system.

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