Question

In: Advanced Math

Let R be a commutative domain, and let I be a prime ideal of R. (i)...

Let R be a commutative domain, and let I be a prime ideal of R.

(i) Show that S defined as R \ I (the complement of I in R) is multiplicatively closed.

(ii) By (i), we can construct the ring R1 = S-1R, as in the course. Let D = R / I. Show that

the ideal of R1 generated by I, that is, IR1, is maximal, and R1 / I1R is isomorphic to the

field of fractions of D. (Hint: use the fact that everything in S-1R can be written in the

form s-1r, where s ∈ S and r ∈ R. The first step is to show that IR1 ∩ R = I).

Solutions

Expert Solution


Related Solutions

Let R be a commutative ring with unity. If I is a prime ideal of R,...
Let R be a commutative ring with unity. If I is a prime ideal of R, prove that I[x] is a prime ideal of R[x].
Let R and S be commutative rings with unity. (a) Let I be an ideal of...
Let R and S be commutative rings with unity. (a) Let I be an ideal of R and let J be an ideal of S. Prove that I × J = {(a, b) | a ∈ I, b ∈ J} is an ideal of R × S. (b) (Harder!) Let L be any ideal of R × S. Prove that there exists an ideal I of R and an ideal J of S such that L = I × J.
Let R be a commutative ring with identity with the property that every ideal in R...
Let R be a commutative ring with identity with the property that every ideal in R is principal. Prove that every homomorphic image of R has the same property.
9.2.6 Exercise. Let R = Z and let I be the ideal 12Z of R. (i)...
9.2.6 Exercise. Let R = Z and let I be the ideal 12Z of R. (i) List explicitly all the ideals A of R with I ⊆ A. (ii) Write out all the elements of R/I (these are cosets). (iii) List explicitly the set of all ideals B of R/I (these are sets of cosets). (iv) Let π: R → R/I be the natural projection. For each ideal A of R such that I ⊆ A, write out π(A) explicitly...
let R = Z x Z. P be the prime ideal {0} x Z and S...
let R = Z x Z. P be the prime ideal {0} x Z and S = R - P. Prove that S^-1R is isomorphic to Q.
Let R be a ring (not necessarily commutative), and let X denote the set of two-sided...
Let R be a ring (not necessarily commutative), and let X denote the set of two-sided ideals of R. (i) Show that X is a poset with respect to to set-theoretic inclusion, ⊂. (ii) Show that with respect to the operations I ∩ J and I + J (candidates for meet and join; remember that I+J consists of the set of sums, {i + j} where i ∈ I and j ∈ J) respectively, X is a lattice. (iii) Give...
Let R be a commutative ring with unity. Prove that f(x) is R[x] is a unit...
Let R be a commutative ring with unity. Prove that f(x) is R[x] is a unit in R[x] iff f(x)=a is of degree 0 and is a unit in R.
10.3.6 Exercise: Product of Pairwise Comaximal Ideals. Let R be a commutative ring, and let {A1,...,An}...
10.3.6 Exercise: Product of Pairwise Comaximal Ideals. Let R be a commutative ring, and let {A1,...,An} be a pairwise comaximal set ofn ideals. Prove that A1 ···An = A1 ∩ ··· ∩ An. (Hint: recall that A1 ···An ⊆ A1 ∩···∩An from 8.3.8).
For an arbitrary ring R, prove that a) If I is an ideal of R, then...
For an arbitrary ring R, prove that a) If I is an ideal of R, then I[ x] forms an ideal of the polynomial ring R[ x]. b) If R and R' are isomorphic rings, then R[ x] is isomorphic to R' [ x ].
We’ll say a polynomial f(x) ∈ R[x] is prime if the ideal (f(x)) ⊂ R[x] is...
We’ll say a polynomial f(x) ∈ R[x] is prime if the ideal (f(x)) ⊂ R[x] is prime. If F is a field with finitely many elements (e.g., Z/pZ), prove that f(x) ∈F [x] is prime if and only if it’s irreducible.
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT