Re: mathlib

[Dirk Laurie <dirk.laurie@...>]

2014-04-08 11:31 GMT+02:00 Eric Wing <ewmailing@gmail.com>:

> Just my data point, but I don't remember ever encountering those
> functions or hyperbolic geometry until I went to grad school and even
> that was kind of a fluke. I went through the University of California
> system in an engineering major that was jointly administered by the EE
> and CS departments.
>
> I finally encountered hyperbolic geometry in a graduate level elective
> course for scientific visualization

For mathematicians, the three sine rules for triangles with sides a,b,c,
and angles A,B,C have all the elegance and beauty of a Bach fugue.

Elliptic geometry: sin(A)/sin(a) = sin(B)/sin(b) = sin(C)/sin(c)
Euclidean geometry: sin(A)/a = sin(B)/b = sin(C)/c
Hyperbolic geometry: sin(A)/sinh(a) = sin(B)/sinh(b) = sin(C)/sinh(c)