Lagresquare
Duy Nguyen Khanh Utilities iPhoneiPadiPod touch
Lagresquare is a free Utilities app for iPhone and iPad by Duy Nguyen Khanh. Requires iOS 14.0. Updated April 28, 2026.
- Price
- Free
- on the App Store
- Size
- 2 MB
- Age 4+
- Updated
- Apr 28
- 2026 · v1.0
Screenshots
About Lagresquare
The application is based on Lagrange's four square theorem, Fermat's sum of squares theorem, and Diophantine equation theory. The core highlight is the Lagrange's four square decomposition function, which can quickly decompose any natural number into which four square numbers it is composed of. It can also switch to two square or three square modes to observe different representations. The theorem tells us that every natural number can be represented as the sum of four squares, which is a milestone in the history of mathematics. The geometric visualization function converts abstract numbers into intuitive graphics. The grid view displays the area relationship of square numbers, the spiral view shows the beauty of number rotation, and the circular view reveals proportional distribution. These three modes provide users with unique mathematical insights. The Statistics Center will analyze the three representations of r ₂ (n), r ∝ (n), and r ₄ (n) for you. By comparing the representations of 1 to 20 through dynamic bar charts, the patterns behind the numbers are clear at a glance. Module 4 conditional validator gradually demonstrates the mathematical principle of sum of squares, allowing you to understand why certain numbers cannot be represented. The special topic on Fermat's sum of squares theorem focuses on the magical property of prime numbers: only prime numbers with p ≡ 1 (mod 4) can be written in the form of a sum of squares. Introduction to the Diophantine Equation: Understanding the History, Types, and Solution Methods of Equations. The calculation history function automatically saves each exploration record.
App privacy
The developer, Duy Nguyen Khanh, reported these privacy practices to Apple.
Data Not Collected
The developer does not collect any data from this app.