degrees and radians.

[Fernando Pérez]

Tim Hammerquist wrote:

> My only intent in mentioning POSIX was that on most *nix systems (esp.
> POSIX ones), you can #include<math.h> and compile and expect to call
> a sin() function (that, btw, takes its argument in radians). Other
> PC-oriented operating systems lack a standard math lib "out-of-the-box".
> 

BTW, this isn't really a unix-or-not issue, it's simply that mathematically, 
the 'natural' form of all trig functions (their power series expansion) 
requires their arguments to be expressed in radians: the period of sin(x) is 
simply 2*pi, 6.1428..., whatever you want to call it. It's _not_ 360: 

sin(0) == 0 ; sin(360) ~ 0.96.

Scientific calculators simply have a 'deg' mode which on the fly converts back 
and forth between degree input and radians for internal work, but that's 
simply a user convenience (because degrees are more conveninent for some 
'everyday' use as angular measurement units).

Just a little detail.

Cheers,

f.