Domain and Codomain

[@OSAHON-EGHOSAMIRACLE-vg7eq]

Thank you sir, you've really helped a lot

[@Henry_In_Canada]

Sorry to bother you. I don't get the purpose of a codomain. I mean a range can be { 1, 2, 3, 4 and all the positive integer} so technically codomain can be "set of positive integer""set of Integer" or "set of R" because it's just all included. Another possible situation that I can imagine is Y(codomain) is another thing just like X(domain) but just another one, once compare mathematicians use the range of X to compare with the domain of Y.

[@TravisCollierMath]

Codomain is useful when looking at surjective functions

[@jakescott6927]

Yessss thank you man you're a life saver - had so many ahhhhh moments there

[@TravisCollierMath]

Glad it helped

[@Sophiaphia_phia]

I just don't understand how there can be an output in the codomain that doesn't have an input. How would you determine what the co-domain is on a graph, or with just an equation (w/o the illustration)?