Did this video help you?
Language of Functions (CIE A Level Maths: Pure 1): Revision Note
Language of Functions
Language of functions
- The language of functions has many keywords associated with it that need to be understoodĀ
Ā
What are mappings?
- A mapping takes an āinputā from one set of values to an āoutputā in another
Ā Ā
- Mappings can be
- āmany-to-oneā (many āinputā values go to one āoutputā value)
- āone-to-manyā
- āmany-to-manyā
- āone-to-oneā
What is the difference between a mapping and a function?
- A function is a mapping where every āinputā value maps to a single āoutputā
- Many-to-one and one-to-one mappings are functions
- Mappings which have many possible outputs are not functions
Notation
- Functions are denoted by the notation f(x), g(x), etc
- eg. f(x) = x2 - 3x + 2
- Or the alternative notation
- eg. f : x ā¦ x2 ā 3x + 2
Sets of numbers
- Functions often involve domains and ranges for specific sets of numbers
- All numbers can be organised into different sets ā, ā¤, ā, ā
Ā Ā
- So ā is a subset of ā¤ etc
- ā¤- would be the set of negative integers only
Domain
- The domain of a function is the set of values that are allowed to be the āinputā
- A function is only fully defined once its domain has been stated
- RestrictionsĀ on a domain can turnĀ many-to-oneĀ functions intoĀ one-to-oneĀ functions
Ā
Range
- The range of a function is the set of values of all possible āoutputsā
- The type of values in the range depend on the domain
Ā
Worked example
You've read 0 of your 5 free revision notes this week
Sign up now. Itās free!
Did this page help you?