Whelp, I’ve been getting that wrong for some time now, thanks.
Ah, apparently “range” is ambiguously used as both “codomain” and “image”. I think I was taught it as codomain (before I was taught that word), and then at some point started to think of codomain as “the one that isn’t the range”.
Whelp, I’ve been getting that wrong for some time now, thanks.
Ah, apparently “range” is ambiguously used as both “codomain” and “image”. I think I was taught it as codomain (before I was taught that word), and then at some point started to think of codomain as “the one that isn’t the range”.
https://en.wikipedia.org/wiki/Range_(mathematics)
It’s older terminology. Everyone says image now.