Re: How to simplify ArcSin formula

*To*: mathgroup at smc.vnet.net*Subject*: [mg123286] Re: How to simplify ArcSin formula*From*: Ray Koopman <koopman at sfu.ca>*Date*: Wed, 30 Nov 2011 03:21:44 -0500 (EST)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*References*: <jb2hsp$5df$1@smc.vnet.net>

On Nov 29, 4:06 am, David Sagan <david.sa... at gmail.com> wrote: > I am trying to discover how to simplify xxx where xxx is defined to > be: > xxx= t + ArcSin[aa] - ArcSin[aa Cos[t] + Sqrt[1 - aa^2] Sin[t]] > with > -1 < aa < 1 > The answer I know is xxx = 0 [...] It is ? xxx = t + ArcSin[aa] - ArcSin[aa Cos[t] + Sqrt[1 - aa^2] Sin[t]]; xxx /. t -> Pi/2 % /. aa -> 1/2 Pi/2 + ArcSin[aa] - ArcSin[Sqrt[1 - aa^2]] Pi/3