Mathematics for IGCSE & O level - Functions (Section 2 - No. 25)
Functions can be described as one-to-one or many-to-one. Which of the following statements are true?
A one-to-one function always maps each element of the domain to a unique element of the range.
A many-to-one function maps two or more elements of the domain to a single element of the range.
A function can be both many-to-one and one-to-one simultaneously.
A function is never a one-to-many function.
설명
A function is one-to-one or many-to-one, never one-to-many. One-to-one means a unique output for each input. Many-to-one means multiple inputs can have the same output.