if I'm defining the range of a function would the following be valid documentation?
Function and rule:
f(x)=x^2
Range f(x) = {f(x)|f(x)>=0}
or is it better to write the range similar to the following.
since,
f(x)=y
then,
Range f(x) = {y|y>=0}
My question is just which is the preferred method of documentation of the mathematician world?