Why is f ( n ) = n 3 not an onto function?I was doing...
Why is not an onto function?
I was doing an example in a book where it asked which of these functions are one to one, the answer in the back said for that it is a one to one function. Then it asked which of the functions from the previous example are onto and was not included in the list of onto functions.
In a later example, a question asked which of these functions is a bijection, the answer included
This is confusing because doesn't a function have to be both an onto and one to one to be a bijection? Why would the book say it was not a onto in a previous example yet declare it to be a bijection? Is the book wrong?