johndcook.com > blog
Closed-form minimal surface solutions
2+ day, 2+ hour ago —...Jean Baptiste Marie Meusnier discovered two of these in 1776, namely... ...helicoild u(x, y) = tan−1(y/x) u(x, y) = cosh−1(a (x² + y²)½) / a Heinrich Scherk...
johndcook.com > blog
Fundamental solution
3+ day, 11+ hour ago —...Cook.... ...So if L is a linear differential operator and F is a fundamental...
johndcook.com > blog
No matter how dubious
3+ day, 12+ hour ago —...To use Iain McGilchristâs metaphor from âThe Master and His Emissary... ...I was convinced it was a footnote in Boyce and DiPrima, but could...
johndcook.com > blog
Superhyperbola
6+ day, 10+ hour ago —...First of all, the superellipse had an advocate, Piet Hein.... ...Piet Hein used the prefix super– to refer to increasing the exponent...
johndcook.com > blog
Diagram chasing | visualizing five lemma as a game
1+ week, 7+ hour ago —...edge: blue […] The post The glass disk game first appeared on John... ...Cook. The glass disk game is played on a grid....
johndcook.com > blog
Voyager’s slingshot maneuvers
1+ week, 2+ day ago —...Note that before encountering Jupiter, Voyager was moving well below... ...When Voyager 2 passed Jupiter, Saturn, and Uranus, each of these...
johndcook.com > blog
Advantages of Reed-Solomon codes over Golay codes
1+ week, 2+ day ago —...Thereâs a reason CDs use Reed-Solomon codes and not Golay codes... ...After leaving Saturn, the software was upgraded to use Reed-Solomon...
johndcook.com > blog
Hand calculating exp(x)
1+ week, 3+ day ago —...The previous post mentioned that Martin Gardner announced that Ramanujan...
johndcook.com > blog
Very accurate pi approximation
1+ week, 3+ day ago —...Incidentally, Martin Gardner announced on April Fool’s day in 1975... ...Cook....