1
Show that each of the following numbers is algebraic over by finding the minimal polynomial of the number over
for with
(a) (c)
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Show that each of the following numbers is algebraic over by finding the minimal polynomial of the number over
for with
(a) (c)
Find a basis for each of the following field extensions. What is the degree of each extension?
over
over
over
over
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over
over
over
over
(a) (c) (e)
Find the splitting field for each of the following polynomials.
over
over
over
over
(a)
Consider the field extension over
Find a basis for the field extension over Conclude that
Find all subfields of such that
Find all subfields of such that
Show that is a field with eight elements. Construct a multiplication table for the multiplicative group of the field.
Use the fact that the elements of are 0, 1, and the fact that
Show that the regular 9-gon is not constructible with a straightedge and compass, but that the regular 20-gon is constructible.
Prove that the cosine of one degree () is algebraic over but not constructible.
Can a cube be constructed with three times the volume of a given cube?
False.
Prove that is an algebraic extension of but not a finite extension.
Prove or disprove: is algebraic over
Let be a nonconstant polynomial of degree in Prove that there exists a splitting field for such that
Prove or disprove:
Prove that the fields and are isomorphic but not equal.
Let be an algebraic extension of and an algebraic extension of Prove that is algebraic over [Caution: Do not assume that the extensions are finite.]
Suppose that is algebraic over and is algebraic over Let It suffices to show that is algebraic over some finite extension of Since is algebraic over it must be the zero of some polynomial in Hence is algebraic over
Prove or disprove: is a field.
Let be a field of characteristic Prove that either is irreducible over or splits in
Let be the algebraic closure of a field Prove that every polynomial in splits in
If every irreducible polynomial in is linear, show that is an algebraically closed field.
Prove that if and are constructible numbers such that then so is
Show that the set of all elements in that are algebraic over form a field extension of that is not finite.
Let be an algebraic extension of a field and let be an automorphism of leaving fixed. Let Show that induces a permutation of the set of all zeros of the minimal polynomial of that are in
Show that Extend your proof to show that where
Since is a basis for over Since or 4. Since the degree of the minimal polynomial of is 4,
Let be a finite extension of a field If show that is a splitting field of for some polynomial
Prove or disprove: Given a polynomial in it is possible to construct a ring such that has a root in
Let be a field extension of and Determine
Let be transcendental over Prove that either or is also transcendental.
Let be an extension field of and be transcendental over Prove that every element in that is not in is also transcendental over
Let not in Then where and are polynomials in with and coefficients in If is algebraic over then there exists a polynomial such that Let Then
Now multiply both sides by to show that there is a polynomial in that has as a zero.