Recent content by DanielThrice

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    Prime & Maximal Ideals of $\mathbb Z_7$ & $\mathbb Z_3 \times \mathbb Z_5$

    I'm working on prime an maximal ideals. My partner and I are studying for our final exam and got conflicting answers. The question was to find all of the prime and maximal ideals of \mathbb Z_7. My answer was that because a finite integral domain is a field, the prime and maximal ideals...
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    Show a ring is idempotent 2

    This is my progress so far... Well, call the matrix M. Then you want that (Mx+B)^2=Mx+B in M2R[x][/math]. So we just have to perform the calculation and see what we get, (Mx+B)^2=MxMx + MxB + BMx+B^2 = M^2x^2+(MB + BM)x + B^2 (the x-terms act like this (commutatively) by definition)...
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    Show a ring is idempotent 2

    My professor gave us this query at the end of class, it contained two parts. 1. Show a ring is idempotent 2. Consider the degree one polynomial f(x) is an element of M2(R)[x] given by f(x) = [0 1 ______0 0]x + B (so f(x) = the matrix []x + B). For which B is an element of M2(R), if any...
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    Proving Subgroups and Cosets in RingsExploring Subgroups and Cosets in Rings

    Thanks Ivy, helped a lot I figured it out. I like how you reworded it.
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    Proving Ring Properties of R: A Step-by-Step Guide

    I'm working with elementary rings, and my professor gave me about ten of these to start but it seems like a lot of work with how he managed it. I know you guys don't answer homework so I chose so I can do the others. Any help would be greatly appreciated, the groups were easy but the rings are a...
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    Proving Subgroups and Cosets in RingsExploring Subgroups and Cosets in Rings

    Original Query: I'm beginning to look at rings for the first time and was given this to start with: Let R = < R, +, *> (* means multiplication) be a ring, and let I < R be an additive subgroup of < R, + >. Consider the set of cosets R/I = {a + I: a is an element of R} equipped with...
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    Is y'' = y solvable by using a homomorphism and understanding its kernel?

    Wait did I mess myself up...the original equation is % (f) = f '' - f so the homomorphism doesn't change that much, it just becomes (f + g) '' - (f + g) = f '' + g '' - f - g. Well any functions in the reals added to other functions of the reals gets you another function of the real, so % is a...
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    Is y'' = y solvable by using a homomorphism and understanding its kernel?

    Is there an easy way to prove that these are the only three?
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    Is y'' = y solvable by using a homomorphism and understanding its kernel?

    So the kernel would just be cos, sin, and e^x correct?
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    Is y'' = y solvable by using a homomorphism and understanding its kernel?

    Nevermind, lol, that's what a homomorphism is. I said the kernel is just all of the constants: f ' (x) = 0 (Integrate) f (x) = C How about if we have a different function, % : G to G defined by % (f) = f '' - f ? Homomorphism? (f + g) '' + (f + g) = f '' + g '' + f + g. Well any...
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    Is y'' = y solvable by using a homomorphism and understanding its kernel?

    Of course not, the constants are the only functions with no change in how they change over time, that's why they are constants. But how do I know to look for the zero derivatives?
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    Is y'' = y solvable by using a homomorphism and understanding its kernel?

    Let G denote the set G = {f : R → R | f is infinitely differentiable at every point x ∈ R}. Prove that G is a group under addition. Is G a group under multiplication? Why or why not? I have proved this after much trouble, using the axioms of group theory, and I think I understand the...
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    Proving Q/Z isomorphic to U∗: Roots of Unity in C

    Show that Q/Z is isomorphic to the multiplicative group U∗ consisting of all roots of unity in C. (That is, U∗ = {z ∈ C|zn= 1 for some n ∈ Z+}.) I don't really understand how to prove this isomorphism
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    Proving Equivalence Relations in Group Theory: Centralizer Math Problem

    H is CG(a) in this case. The operation m' is just * (written g*h or just gh). We want to show * : CG(a) x CG(a) -> CG(a) This means that for any g, h in CG(a) We need to show gh or g * h is in CG(a) g in CG(a) means what? ga = ag (commutative) similarly ha = ah How do we show gh is...
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    Understanding Additive Factor Group Q/Z

    Alright, so I showed this: We have that if r+Z is an element of R/Z, and the order of r + Z = n, nr is an element of Z implies that r is an element of Q. But what about this: Show that Q/Z is isomorphic to the multiplicative group U∗ consisting of all roots of unityin C. (That is, U∗ =...
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