Shipping Estimate
USA
- USA
- CAN
- USA
- CAN
Ships within 48 hours · Estimated delivery Jul 5 - Jul 10
Promo Codes Available:
For Your Every Summer RSVP, with Code: SUMMER15
Description
Fermat Equation over several fields and other historical mathematical conjecturesAs a teacher of several mathematics subjects at university level, and writer of several books that preceded to this one, and as a result of my goal to try to explain what seemed difficult as something easy, for a few years I began to investigate in several mathematics areas about possible simple proofs to complex mathematical problems. This book contains the results of these investigations, referring to Fermat's last theorem, as well as the existence
As a teacher of several mathematics subjects at university level, and writer of several books that preceded to this one, and as a result of my goal to try to explain what seemed difficult as something easy, for a few years I began to investigate in several mathematics areas about possible simple proofs to complex mathematical problems. This book contains the results of these investigations, referring to Fermat's last theorem, as well as the existence of solutions for the Fermat equation in other fields such as quadratic integers and Gaussians, and conjectures such as Collatz conjecture and Goldbach strong conjecture.
Shipping Notes
- Free Standard Shipping on $100+ Orders to the USA.
- Except Preorder products are shipped in 48 hours.
- Delivery to the USA:
- Standard Shipping : 3-10 business days
- If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
- We offer a 30-day return/exchange service after receiving.
- Final sale items are not eligible for returns or exchanges.
- To process your return/exchange, please contact us at [email protected]
- Please click here for more details>>> Return & Exchange Policy
4.6 ★★★★★
Based on 426 reviews
Sort
Product Reviews
★★★★★ 5
Timex. Life is ticking.
Color: Black, Size: One Size
A family member is headed off to Navy boot camp and is required to have a watch-a black watch. But...it cannot be anything in the realm of, be like, or indeed be an Apple Watch. The search began for a simple timepiece. Economy was important since after the 8 weeks of boot camp ended, use of the current watch would be resumed. Enter Timex...(the world's largest manufacturer of watches and mechanical time fuses). During the Amazon search there were all manner of economically (actually cheap) watches noted to be available, so many that it was simply overwhelming. Timex...tried and true since 1854 (just a fun fact, but actually attests to the quality of the company) was the chosen one. A simple but reliable timepiece was required, and certain qualifications were needed. First, it had to be an accurate time keeper and have a second hand, and have a date indicator. Secondly, there had to be an element of water resistance (this is Navy boot camp after all, so water is important!). Thirdly, it had to be black. Fourth, no bells or whistles whatsoever. Finally, a face with 24 hour/military time would be a bonus. This Timex Rugged Core Expedition Analog Watch fit the bill. Upon arrival it was packaged in a traditionally square box the size of the watch, no frills but sturdy enough to ward off damage during shipping. Once opened the first thing noticed was the face of the watch. It was black, with white numerals in both standard and 24 hour/military time, had a red second hand, luminescent hour and minute hands, and date indicator. The nylon band was also black, had ridges, and had a fastener like a belt. At the end of the band were two extrusions which seemed to lock the excess band into place once it was fastened. After wearing a number of days, the watch has kept excellent time matching the Apple Watch. Both watches were worn on the same arm at the same during the day and during sleep. They were worn during regular daily activities, during exercise and during strenuous garden work such as hauling, digging holes, dragging 40 lb bags, etc. Time was checked multiple times per day, and the time on each watch was exactly the same every time checked. The Timex was water resistant during a 5 minute shower and while submerged water. This is not a dive watch but, according to the ad, is water resistant to 50 feet for light swimming. The performance of this watch has been more than satisfactory executing in stellar fashion everything it was stated to be able to do. I can recommend this watch for boot camp purposes without reservation.
Top 3 Likes:
-Reliable keeping accurate time, has military time numerals
-Is water resistant as tested
-Is black, attractive with luminescent hands, second hand, date, and light up face
Top 3 Dislikes:
-The band is stiff and somewhat difficult to latch
-The two little extrusions do anchor the band, but are difficult to undo to take off the watch
-Only two dislikes!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on September 28, 2024
★★★★★ 5
Timesx quality still rules.
Color: Black, Size: One Size
Excellent everyday watch. Stylish, easy to read, and accurate. Needed a knock around watch and this puts up with it's share of abuse. It's a bit more expensive than some others in this class, but Timex is well-worth the money in quality. I use mine for eveything except when I need something more formal.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on December 1, 2025
★★★★★ 1
Dependability and accuracy
Color: Black, Size: One Size
This watch is awful, I had it for a month and it lags behind and does not keep the right date. I am a nurse so I need to have accuracy and dependability and this watch is not it.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on February 16, 2026
★★★★★ 5
Good stuff
Color: Black, Size: One Size
fits well, good for every day wear, looks great, great value. the black is a good color. would have loved some more insight into how to change the date but other than that would def recommend
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on January 31, 2026
★★★★★ 5
Beutiful and rugget watch.
Color: Black, Size: One Size
Beutiful aspect, great and rugget watch, looks great on the wrist, nice and clear backlight, very ligth watch.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 6, 2026
recommand products
Solenostemon scutellarioides 'Red Coat' ~ Red Coat Coleus
73.57
A Beginner's Guide to Prayer: The Orthodox Way to Draw Closer to God
10.95
New England Patriots vintage style Canvas Print, vintage football decor, football room decor, room decor for men, apartment decorating ideas
43.00
Cleveland Cavaliers vintage style Canvas Print, vintage basketball, basketball room decor, basketball wall decor, basketball gift ideas
43.00
Veronica spicata 'Pink Goblin' ~ Pink Goblin Veronica
121.99