you explained it better than my teacher, when i asked him the difference between one to many and many to one he said it was the same thing, I wouldve went along with that if i hadnt came across this video, thank you
The domain is not 'an input', but the set of all possible inputs, i.e. the set of all possible x values which the function can take. The term 'codomain' is the set of all possible outputs, i.e. the set of all possible y values which the function can take. However, in IGCSE Add Math, we don't use this term - we use the word 'range' instead. So, for the function y = sqrt(x-1), the domain would be the set of all x values greater than or equal to 1, and the range (or codomain) would be the set of all y values greater than or equal to zero.
