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1. Individually: Spend 1mins on your own thinking about key words, concepts taking notes of your ideas
2. Share with your partner and come up with your joint definition
Aim: Defining functions using the concept of mappingsExample: Pets owned by children in a particular street
Input : Domain: 4 children who live in a particular street
Use this example to clarify terminology:
Possible Outcome: Co-domain is the set of all possible pets
Actual Output : Range is {dog, cat, rabbit, fish} since only these four different types of pet are owned by this particular set of children
Use this example to clarify terminology:
Domain: 4 mums at a toddler groupCo-domain is children present at this groupRange same as co-domain since co-domain is defined as children present at this group rather than all children
Use this example to clarify terminology:
Domain: 6 children who live in a particular streetCo-domain allowed ages for toddler group(up to 4years)Range is {0,1,3,4} since there is no 2year old in this particular group
How could you classify different types of mappings?
There are four types of possible mappings:
“one – to – one”
“one – to – many”
“many – to – one”
“many – to – many”
A function is a special type of mapping such that each member of the domain is mapped to one, and only one, element in the co-domain.DOMAINThe DOMAIN is the set of ALLOWED INPUTS TO A FUNCTION.CO-DOMAINThe Co-domain is the set of POSSIBLE OUTPUTS FROM A FUNCTIONRANGEThe range is a subset of the codomain, it is the set of ACTUAL OUTPUTS
More terminology:
This is a ………………. mapping.
For every value of x, there is one value of 1 – 3x, and no two objects map to the same image.
The co-domain and the range is also Q, since all rational numbers are the image of another rational number under this mapping.
This mapping is also a function as there is only one possible image for each object.