# Is there always a maximal ideal?

Is there always a maximal ideal? Every proper ideal is contained in a maximal ideal, in a commutative ring with identity. The statement is: In a commutative ring with 1, every proper ideal is contained

## Is there always a maximal ideal?

Every proper ideal is contained in a maximal ideal, in a commutative ring with identity. The statement is: In a commutative ring with 1, every proper ideal is contained in a maximal ideal.

## Are prime ideals maximal?

As with commutative rings, maximal ideals are prime, and also prime ideals contain minimal prime ideals. A ring is a prime ring if and only if the zero ideal is a prime ideal, and moreover a ring is a domain if and only if the zero ideal is a completely prime ideal.

## What is maximal ideal of prescription?

For R[x]: The maximal ideals of R[x] corresponds to the irreducible polynomials over R. Then f(x)=(x−α)(x−ˉα) will be a degree two irreducible polynomial over R. The linear polynomials corresponds to the point in the real line.

## Which of the following is maximal ideal of Z * Z?

If we let J={(a,a):a∈Z} then J≅Z given the by isomorphism (a,a)↦a. This is a field, which implies (7,7)J={(7a,7a):a∈Z} is a maximal ideal. But (7,7)J⊊{(7a,7b):a,b∈Z} which is a counterexample to the claim that (7,7)J is maximal.

## Is 2Z a maximal ideal?

The ideal 2Z ⊂ Z is prime and maximal, so that 2Z/8Z ⊂ Z/8Z is a prime and maximal ideal. The ideals Z,4Z,8Z ⊂ Z are neither prime nor maximal, so that the ideals Z/8Z,4Z/8Z,(0) ⊂ Z/8Z are neither prime nor maximal.

## Which ring has no maximal ideal?

A commutative ring R has no maximal ideals if and only if (a) R is a radical ring.

## Is Za a field?

The integers are therefore a commutative ring. Axiom (10) is not satisfied, however: the non-zero element 2 of Z has no multiplicative inverse in Z. That is, there is no integer m such that 2 · m = 1. So Z is not a field.

## Can a ring have more than one maximal ideal?

It is possible for a ring to have a unique maximal two-sided ideal and yet lack unique maximal one sided ideals: for example, in the ring of 2 by 2 square matrices over a field, the zero ideal is a maximal two-sided ideal, but there are many maximal right ideals.

## Is real number a field?

The first says that real numbers comprise a field, with addition and multiplication as well as division by non-zero numbers, which can be totally ordered on a number line in a way compatible with addition and multiplication.

## Is R+ A field?

Since we found one vector which spans, R+ is a one-dimensional vector space over the field R. If we use a subfield of R for F, then depending on which x we choose, log2 x may or may not be an element of F, and so we will need more than one element in our basis for this other vector space.