Re: Trigonometric math functions

*To*: mathgroup at smc.vnet.net*Subject*: [mg44569] Re: Trigonometric math functions*From*: poujadej at yahoo.fr (Jean-Claude Poujade)*Date*: Fri, 14 Nov 2003 04:43:16 -0500 (EST)*References*: <boig47$og2$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

"Bruno" <bpa at BPASoftware.com> wrote in message news:<boig47$og2$1 at smc.vnet.net>... > Hi all, > > I would like to implement an arc cos function on a 16 bits µcontroller > (optimized sin() and cos() function are welcome). > > Does someone have some sources or an algorythm in this way ? > > Thanks in advance, > > Regards. Why not simply use a series expansion? In[1]:=Series[ArcCos[x],{x,0,3}]//Normal Out[1]=Pi/2 - x - x^3/6 In[2]:=acos[0]=Pi/2; acos[1]=0; acos[x_ /; 0<x<1] := Pi/2-x-x^3/6 ; acos[x_ /; x<0] := Pi-acos[-x]; In[3]:=Plot[{ArcCos[x],acos[x]},{x,-1,1}] No difference can be seen with a naked eye! --- jcp