atan(3) on Linux
The text 674f12f6466f, as Debian 2.2 (Potato), Debian 2.1 (Slink), Debian 2.0 (Hamm), Debian 1.3 (Bo), Debian 1.2 (Rex), Debian 1.1 (Buzz) shipped it.
arc tangent function
The text 674f12f6466f, as Debian 2.2 (Potato), Debian 2.1 (Slink), Debian 2.0 (Hamm), Debian 1.3 (Bo), Debian 1.2 (Rex), Debian 1.1 (Buzz) shipped it.
arc tangent function