Question

what function is a one to one function?

Answer 1

If every element of domain has unique image from co-domain, then the function is one-one

Answer 2

take a graph of any function and put a horizontal line on it if that line touches the graph at one point only then it is one to one function but if this line cuts the graph on more than 1 point then it is not.

Answer 3

So therefore then when tis one-one and thus can it be called a surjective or injective because my lecturer calls a one-one a surjective but youtube calls it injective so i am confused.

Answer 4

surjective -> image (range) = codomain
injective -> codmain > image
injective surjective = bijective (one to one correspondence)

Answer 5

One to one function and one to one correspondence are not the same thing.

Answer 6

then one-one function is injective as an 'onto' is a surjective. right?!

Answer 7

right...