# CTK Insights

• ## Pages

16 Aug

### Uneducated Guesses

Tweet Just received a review copy of a new book from Princeton University Press: Uneducated Guesses by Howard Wainer. Have been reading it for the last hour - an absolutely absorbing book. Feels like a must for politicians, reformers, educators - math educators in particular. From Introduction: In the chapters to follow I will show […]

14 Aug

### One sheet hyperboloid

TweetA hyperbola has two axes of symmetry: one that crosses the hyperbola while the other does not. Two different 3D shapes are obtained when a hyperbola is made to rotate around its axes. Two sheet hyperboloid One sheet hyperboloid The equation of one is and that of the other is The one sheet hyperboloid has […]

10 Aug

### When am I ever going to use this? Why do we need to learn this?

TweetProbably every math teacher has the experience of facing such questions; most likely the students who asked them were not looking for the answers as arguments to study mathematics, but rather in support of their conviction that the effort is not necessary. Most of the answers teachers give perfectly serve this purpose. I wrote about […]

09 Aug

### Biblical π and Gematria

TweetAccording to [P. Beckmann, p. 12], by 2000 BC, the ancient Babilonians already new that π is close to 25/8 (≈ 3.125), while the Egyptians estimated it as 4(8/9)² (≈ 3.1605). Beckmann, as many others, do not conceal his astonishment that in the Bible the apparent estimate is a simplistic 3. This is based on […]

08 Aug

### What is this geometry theorem?

TweetI just received a review copy of Fascinating Mathematical People by Donald Albers and Gerald Alexanderson (Princeton University Press, 2011). Right now I am into something else, but could not forego getting a quick first impression. Looks like I am going to enjoy reading the book. Here's something that caused me a healthy chuckle. I […]