2023-07-09
Tracing closed curves with epicycles
A fun application of the discrete Fourier transform
Juan Carlos Ponce Campuzano
1--14
Origami paper cup
From paper folding to data analysis and algebraic explorations
Lingguo Bu, Harvey Henson
15--25
Building an Analog Clock with Complex Numbers
David Glassmeyer, Binita Patel
26--34
Filling vessels
An exciting way to investigate functional dependencies
Laura Sergi, Stefan Götz
35--47
2022-02-17
The Fourier transform (and all its versions, discrete/continuous/finite/infinite), covers deep and abstract mathematical concepts, and can easily overwhelm with detail. In this paper I provide some intuitive ideas of how the discrete Fourier transform (and its version with low frequencies) works and how we can use it to approximate real periodic functions and parametric closed curves by means of trigonometric interpolation.
2022-02-17
The Fourier transform (and all its versions, discrete/continuous/finite/infinite), covers deep and abstract mathematical concepts, and can easily overwhelm with detail. In this paper I provide some intuitive ideas of how the discrete Fourier transform (and its version with low frequencies) works and how we can use it to approximate real periodic functions and parametric closed curves by means of trigonometric interpolation.
2021-11-09
Every object created in GeoGebra has a color property that the user can easily change. Colorcan help identify different objects of the same class. However, if we create lists of objects of thesame class (e.g., a list of circles) and try to change the color of this list, then we notice that allthe objects change color. So how can we create a set of objects of the same class, such that eachelement has a different color? In this article, the author will show an efficient method to colordifferent objects of the same class.
2021-10-04
The authors, using a proof without words style, explore a lesser known variation of the triangle inequality involving the difference between the sum of the lengths of any two sides and the length of the third side. The authors provide a web applet for further exploration.
2012-05-02
We're typesetting articles to be ready for the Spring Conference.2011-07-11
We're happy to announce the creation of a new, peer-reviewed electronic journal to support and sustain the work of the GeoGebra Institute of Ohio, and you're WELCOME to join us!