# What is function? Learn everything about it now!

**Functions **are basically certain mathematical operations that are performed over one or more variable or inputs that basically result in an output. In them, the output depends on the input. In their simplest form, **math functions **look like this: **Y = x + 1. **Considering this form, the X is basically the input, whereas the Y happens to be the output. When you put in a value for x, you would actually be able to calculate Y, which is going to be its corresponding output.

Another means of writing functions is that of replacing Y with f(x). To be honest, Y is just an arbitrary letter, whereas the output of **math functions **can be represented by any letter whatsoever. For example:

Here, you may note, that the name of the function happens to be F, while x is the input value. Now, for the function, f basically takes the value of x and squares it. See how easy learning about **mathematical functions **really is?

## So, what is the evaluation of a function all about?

When learning about **what is a function**, you would also come across the concept of evaluating it. Basically, the evaluation of a function is all about picking varying values as the input for the function so that its output can be found. The input of **algebraic functions **is typically denoted by x, while its output is denoted by y. When you evaluate **functions**, you would actually find that for every choice that you pick for x, there is going to be an end result in the form of a corresponding value for y.

**Are functions really so simple?
**Not always! There are many other far more complicated forms of

**math functions**as well! For example, there are polynomial functions, which are a whole lot more complicated! Take an example and you’ll understand how intricate these can get:

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More topics in Functions | |

Domain and Range | Finding Domain and Range |

Types of Functions | Graphing Functions |

Solving Functions | Examples of Functions |

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