If it has I as a maximal ideal, then R/I is a field.
now suppose that is a maximal ideal of let and choose let see that is an ideal of since we have
so is a "proper ideal" of it's clear that because let if then clearly so we'll assume that suppose that then
and therefore which is a false result. so we must have and so thus hence which contradicts maximality of
the notations are standard and i don't know how you didn't understand them?? is the set of real numbers and
2. I dont understand the notation, what does and what does or mean?
well, if you allow then you'll exactly get the ring which i already mentioned. in this case (your original ring) would be the unique maximal ideal of this new ring
If we allow then R has an identity and therefore a maximal ideal. Prove that in this case the maximal ideal is unique and identify it.
I cant find the maximal ideal, anyone has an idea?
first see that is indeed an ideal of now let be any ideal of not contained in so has an element of the form but then
would have an inverse in and, since is an ideal, we get thus so every proper ideal of is contained in and hence is the unique maximal ideal of