Please explain steps taken and why 21.21 Let R be a PID and I an ideal...
66. Let R be a commutative ring with identity. An ideal I of R is irreducible if it cannot be expressed as the intersection of two ideals of R neither of which is contained in the other. the following. (a) If P is a prime ideal then P is irreducible. (b) If z is a non-zero element of R, then there is an ideal I, maximal with respect to the property that r gI, and I is irreducible. (c) If...
(1) Prove that if R is a PID and P is a prime ideal, then R/P is another PID Show that if I is an arbitrary ideal, then R/I might not be a PID (2) Find an expression for the ged and lem of a pair of nonzero elements a, b in a UFD, and prove that it is correct.
(1) Prove that if R is a PID and P is a prime ideal, then R/P is another PID Show...
74. Let R be a commutative ring with identity such that not every ideal is a principal ideal principal ideal. (b) If I is the ideal of part (a), show that R/I is a principal ideal ring
74. Let R be a commutative ring with identity such that not every ideal is a principal ideal principal ideal. (b) If I is the ideal of part (a), show that R/I is a principal ideal ring
3. Let I be a left ideal of R and let (: R) reRRCI (a) : R) is an ideal of R. If l is regular, then (: R) is the largest ideal of R that is contained in 1 (b) If I is a regular maximal left ideal of Rand AR/I, then (A(R). Therefore J(R) na:R), where /runs over all the regular maximal left ideals of R. Theorem 1.4. Let B be a subset of a left module A...
For context, Cor. L25.8 : Let I =/= (0) be a nontrivial ideal of Z.
Then I is prime if and only if I = (p) for some prime p
4. In Cor. L25.8, we characterized the prime ideals of Z. Give a similiar characterization of the prime ideals in Z, for any n > 1. (Hint: Use problems 2(a) and 3 above)
Suppose R is a principal ideal domain, and let S be a multiplicatively closed subset of R not containing 0. Show that S-R is a principal ideal domain. Let I be an ideal of a principal ideal domain R. Show that R/I is a principal ideal domain if and only if I is prime.
Let R be a UFD, and let So be a set of irreducibles in R. Let S := {ufi.fr: k > 0,[1,...,SE E So, u € R*} (we use the convention that the product fifk is 1 when k=0). (a) Show that S is multiplicatively closed. (b) Suppose / ER, GES. Show that is a unit in S-R if and only if SES. (c) Show that res-'R is irreducible if and only if x is associates with y = {es-R,...
(a) Let R be a commutative ring. Given a finite subset {ai, a2, , an} of R, con- sider the set {rial + r202 + . . . + rnan I ri, r2, . . . , rn є R), which we denote by 〈a1, a2 , . . . , Prove that 〈a1, a2, . . . , an〉 įs an ideal of R. (If an ideal 1 = 〈a1, аг, . . . , an) for some a,...
thanks
Let I be a proper ideal of a commutative ring R with 1. Prove that I is a maximal 3. (10 ideal of R if and only if for every a e R\I, I+(a) : {i+ ar i e I,rE R} = R.
Let I be a proper ideal of a commutative ring R with 1. Prove that I is a maximal 3. (10 ideal of R if and only if for every a e R\I, I+(a) : {i+...
= Let R be a ring (not necessarily commutative) and let I be a two-sided ideal in R. Let 0 : R + R/I denote the natural projection homomorphism, and write ř = º(r) = r +I. (a) Show that the function Ø : Mn(R) + Mn(R/I) M = (mij) Ø(M)= M is a surjective ring homomorphism with ker ý = Mn(I). (b) Use Homework 11, Problem 2, to argue that M2(2Z) is a maximal ideal in M2(Z). (c) Show...