School Life #24: One-to-One and Onto

(Click on the comic if you can't see the full image.)

Bonus Panel

(C)Copyright 2021, C. Burke. "AnthroNumerics" is a trademark of Christopher J. Burke and (x, why?).

Same old stories: boys want girls to be into them, not onto them.

Ob Math: Originally the bonus panel was going to be the map of the relation, but then the Kyung idea occurred to me. When you have a relation of two sets of data, if each member of the input (domain) maps to one distinct member of the output (range), then it is a one-to-one relation. If every member of the output has an input mapped to it then it's "onto". If there's an extra element, then it's not onto. The first comic is one-to-one and onto. The bonus panel is one-to-one but not onto.

The one-to-one relation is mapped below:

I also write Fiction! You can now preorder Devilish And Divine, edited by John L. French and Danielle Ackley-McPhail, which contains (among many, many others) three stories by me, Christopher J. Burke about those above us and from down below. Preorder the softcover or ebook at Amazon.

Come back often for more funny math and geeky comics.