Introduction to Functions (OCR GCSE Maths)

Introduction to Functions

What is a function?

• A function is a combination of one or more mathematical operations that takes a set of numbers and changes them into another set of numbers

• The numbers being put into the function are often called the inputs

• The numbers coming out of the function are often called the outputs

• A function may be thought of as a mathematical “machine”

• A function can be shown in a diagram form

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    • The input is x and the output is y

    • In algebra, this says 5x + 6 = y

What is a mapping diagram?

• A mapping diagram shows a set of different inputs going into the function to become a set of different outputs

  • Transforming inputs into outputs is called mapping

• For example, a mapping diagram for the function   where could be shown as: