Question

What does "one to one" mean when talking about the data of a function?

Answer 1

@zepdrix
@whpalmer4

Answer 2

that means one source, you have one target only,
if x =1 f(x) = f(1)
if x =2, f(x) = f(2) and f(1) \(\neq\)f(2)

Answer 3

So if f(3)=1 and f(-2)=1 a function is still one to one?

Answer 4

nope, must be one-one

Answer 5

So whenever a same y is gotten with two different x's it is not one to one?