"Since G is abelian, ab=ba. Then f(ab)=f(a)f(b)=f(b)f(a)=f(ba). Hence f(G) is abelian." This is technically correct but pedagogically useless. It jumps from f(ab) to the conclusion without explaining why the image group inherits commutativity.
Therefore, f(ab) = f(ba). Hence f(a)f(b) = f(b)f(a), so xy = yx. a book of abstract algebra pinter solutions better
If you have typed that exact phrase into a search engine, you know the struggle. You have likely found the official instructor’s manual (terse, incomplete, and riddled with typos), crowdsourced solutions on Quizlet (often wrong), or disjointed discussions on Math Stack Exchange (helpful, but scattered). This article argues that Pinter’s A Book of Abstract Algebra is a masterpiece in need of a companion—a solution guide that matches the book’s own clarity, pedagogy, and soul. "Since G is abelian, ab=ba
Before introducing the formal definition of a group, Pinter spends a chapter exploring concrete examples: the symmetries of a triangle, the integers under addition, the nonzero reals under multiplication. He builds intuition before rigor. It jumps from f(ab) to the conclusion without
We need to show f(a)f(b) = f(b)f(a). Because f is a homomorphism, f(a)f(b) = f(ab) and f(b)f(a) = f(ba).
In the meantime, keep Pinter’s words in mind. In his preface, he writes: "Mathematics is not a spectator sport." He did not write the book so you could copy answers. He wrote it so you could struggle, discover, and eventually win. A better set of solutions wouldn’t rob you of that struggle—it would just make sure you struggle productively.