2
votes
2answers
77 views

Proof for Surjections

I'm reading through Basic Algebra I (which I enjoy so far. Thoughts on this for self-studying?) and am having a difficult time proving surjection. I believe I understand the concept, but when it comes ...
1
vote
1answer
53 views

How do I prove the definition of a homomorphism?

The question is asking me to prove that $f(a \circ b) = f(a) \circ f(b)$. This I believe is referencing our previous proof which tells us: Assume $g:x \rightarrow y $ is a bijection and for an $a ...
1
vote
1answer
119 views

How does Composition Algebra Relates to Function Composition?

I've read the definition of composition algebra in wikipedia, but I couldn't understand whether it relates to the usual function composition $(\circ)$. Are these two things related at all? ...