Question

What is the range of the function `y=|x|`?

Answer 1

Because `y=absx>=0` the range is `R_f=[0,+oo)`

Answer 2

Let's start with the domain, even though that is not the question.
The domain includes all of the 'X' values in the function which is this case is all X values that are members of the reals between negative infinity to positive infinity.

The range is the set of 'y' values that result from the given domain .
Since the absolute value of any real number is a positive, the range is all y values that are reals and are greater or equal to zero