Re: Simplification question in Mathematica 7

*To*: mathgroup at smc.vnet.net*Subject*: [mg113855] Re: Simplification question in Mathematica 7*From*: Barrie Stokes <Barrie.Stokes at newcastle.edu.au>*Date*: Tue, 16 Nov 2010 05:04:10 -0500 (EST)

Jennifer: You will find that Sqrt[-(((ea - eb)^2 + (na - nb)^2)*(-mb1^2 - mb2^2 + mb2^2*Cos[2*b1] + mb1^2*Cos[2*b2])*Csc[b1 + b2]^4)]/Sqrt[2] // TrigExpand // Simplify will get you what you want, perhaps? HTH BArrie >>> On 15/11/2010 at 9:50 pm, in message <201011151050.FAA09230 at smc.vnet.net>, Jennifer Hatz <btjunkie.org at abv.bg> wrote: > Both FullSimplify and Simplify do nothing on the following expression > Sqrt[-(((ea - eb)^2 + (na - nb)^2)*(-mb1^2 - mb2^2 + mb2^2*Cos[2*b1] + > mb1^2*Cos[2*b2])*Csc[b1 + b2]^4)]/Sqrt[2] > > I found out that it is possible to further simplify it to > Sqrt[((ea - eb)^2 + (na - nb)^2)*Csc[b1 + b2]^4*(mb2^2*Sin[b1]^2 + > mb1^2*Sin[b2]^2)] > > as > FullSimplify[Sqrt[(-(ea - eb)^2 - (na - nb)^2)*(-mb1^2 - mb2^2 + mb2^2*Cos[2*b1] + > mb1^2*Cos[2*b2])*Csc[b1 + b2]^4]/Sqrt[2] - Sqrt[((ea - eb)^2 + (na - > nb)^2)*Csc[b1 + b2]^4*(mb2^2*Sin[b1]^2 + mb1^2*Sin[b2]^2)]] > produces zero > > The question is - is it somehow possible to tell mathematica to convert the > first expression into the second? > Are there any additional commands that work on trigonometric functions > better than Simplify? > > Thanks in advance