Inverse Tangent function

*To*: mathgroup at smc.vnet.net*Subject*: [mg79970] Inverse Tangent function*From*: "Boen S. Liong" <mr_bean_curdy at yahoo.com>*Date*: Fri, 10 Aug 2007 01:38:13 -0400 (EDT)

Please help: Let w1 = tan-1(x) i.e. inverse tangent of x or tan(w1) = x w2 = tan-1(y) i.e. tan(y) = w2 and w3 = w2- w1 problem: find tan(w3) in term of x and y. or better yet: let x= x1/z1 and y= y1/z1 problem:find tan(w3) in term of x and y. I know the formula for tan( u+v) or tan(u-v). but please help for the above. thank you. Boen S. Liong

**Follow-Ups**:**Re: Inverse Tangent function***From:*Andrzej Kozlowski <akoz@mimuw.edu.pl>

**RE: Inverse Tangent function***From:*"Jaccard Florian" <Florian.Jaccard@he-arc.ch>