Consider the ring homomorphism ϕ : Z[x] →R defined by ϕ(x) =
√5.
Let I = {f ∈Z[x]|ϕ(f) = 0}.
First prove that I is an ideal in Z[x]. Then find g ∈ Z[x] such
that I = (g). [You do not need to prove the last equality.]
Prove the following:
(a) Let A be a ring and B be a field. Let f : A → B be a
surjective homomorphism from A to B. Then ker(f) is a maximal
ideal.
(b) If A/J is a field, then J is a maximal ideal.
(a) Find P [Z > 1.26]. (b) Find P [Z > -1.37}. (c) find
P[-1.25
(a)
Find P [Z > 1.26]. (b) Find P [Z > -1.37}. (c) find
P[-1.25<Z<0.37). (d) find z such that P[Z>z]=0.05. (e)
find z such that P[-z<Z<z]=0.99. (f) find the value of k such
that P[k<Z<-0.18]=0.4197