Field theory and polynomials Theorem
Impossibility of squaring the circle
Builds on Squaring the circleTranscendence of piThe degree of a constructible number is a power of two
Statement
The number is not a constructible number. So the circle cannot be squared with straightedge and compass.
Remarks
The proof: every constructible number is algebraic over . If were constructible, then would be constructible and so algebraic. This contradicts the transcendence of .
History
The impossibility was proved in 1882, as a consequence of Lindemann's proof that is transcendental. It had been known for decades that the transcendence of would imply the impossibility.
Reading path
To understand this page from the ground up, read these 60 pages in order. The foundations come first.
- Group concept
- Straightedge and compass construction concept
- Ring definition
- Constructible number definition
- Squaring the circle problem
- Commutative ring definition
- Ideal definition
- Polynomial ring definition
- Ring homomorphism definition
- Subring definition
- Unit of a ring definition
- Zero divisor definition
- Divisibility in a commutative ring definition
- Ideal generated by a subset definition
- Maximal ideal definition
- Two-sided ideal definition
- Degree of a polynomial definition
- Polynomial evaluation definition
- Field definition
- Integral domain definition
- Kernel of a ring homomorphism definition
- Ring isomorphism definition
- Principal ideal definition
- Quotient ring definition
- The only ideals of a field are zero and the whole field statement
- Evaluation homomorphism definition
- Leading coefficient definition
- Root of a polynomial definition
- Subfield definition
- Irreducible element definition
- Euclidean domain definition
- Correspondence theorem for rings statement
- Principal ideal domain definition
- The constructible numbers form a field closed under square roots statement
- Monic polynomial definition
- Universal property of the quotient ring statement
- Irreducible polynomial definition
- Degree of a product statement
- Field extension definition
- R/M is a field iff M is maximal statement
- In a PID a nonzero element is irreducible iff it generates a maximal ideal statement
- Division algorithm for polynomials statement
- Algebraic element definition
- R[x] is an integral domain iff R is statement
- First isomorphism theorem for rings statement
- Intermediate field definition
- Degree of a field extension definition
- Transcendental element definition
- Minimal polynomial of an algebraic element definition
- K[x] is a Euclidean domain statement
- Field generated by adjoining elements definition
- Tower law statement
- Transcendence of pi statement
- The minimal polynomial divides every polynomial vanishing at the element statement
- K[x]/(f) is a field iff f is irreducible statement
- Simple extension definition
- K(a) is isomorphic to K[x] modulo the minimal polynomial statement
- Degree of a simple extension is the degree of the minimal polynomial statement
- The degree of a constructible number is a power of two statement
- Impossibility of squaring the circle statement
Where this leads
1 page builds on this one.
Further reading
- Web https://en.wikipedia.org/wiki/Squaring_the_circle, Impossibility
About this page
| Tag | 0X7CVDE3BG |
|---|---|
| URI | m2://0X7CVDE3BG |
| Kind | statement, theorem |
| Writing | W0 stub |
| MSC | 12F05 |
| Status | This copy of the site has no build data. Run m2 status 0X7CVDE3BG. |
| Uses | Squaring the circle, Transcendence of pi, The degree of a constructible number is a power of two |
Markdown · JSON · Edit on GitHub
What this page needs for W1
- an inventory row: the row of the inventory that the node accounts for (0 of 1)
The writing levels say how complete the text of a page is. They do not measure its truth.