Programming Trig Functions

*To*: mathgroup at smc.vnet.net*Subject*: [mg23890] Programming Trig Functions*From*: dehartre at hotmail.com (BeckyD)*Date*: Thu, 15 Jun 2000 00:51:29 -0400 (EDT)*Organization*: The Math Forum*Sender*: owner-wri-mathgroup at wolfram.com

I am writing a program and I need to convert the ArcCosign from radians to degrees. I have this formula: ArcCos = ArcTan(Sqrt(1-x*x)/x)*180/pi, but it won't work with negative numbers. Any help?