Mathematically, mapping is a term that refers to the "corresponding" relationship between two groups of elements.
Question ②
no
That's for sure
and
only
Each element in set A has a unique element in set B..
The Q 3- 1 map shows that it is both injective and surjective.
Single shot means
Define two different elements in a domain.
Images mapped in the range must be different.
And surjective
This means that every element in an image set must have an original image.
The mapping can correspond to several elements.
And the one-to-one mapping is one-to-one.
It's hard.
as best as one can