Answer:
There are many. Two examples are

Step-by-step explanation:
There are many examples. The simplest is
1 -

It is trivial that

2 -

That function is injective as well.

An example of a function that is NOT injective is

Notice that

<span>There are several examples that can help one remember the definition of expand. To begin with, a balloon can expand when air or water enters it, depending on the type. Cookies often expand when baking due to the leavening agent used in the recipe. When we stretch our bodies, our muscles often expand.</span>