Re: Combine sqrts in denominator

*To*: mathgroup at smc.vnet.net*Subject*: [mg122437] Re: Combine sqrts in denominator*From*: "David Park" <djmpark at comcast.net>*Date*: Fri, 28 Oct 2011 05:37:00 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*References*: <15715639.102984.1319708960115.JavaMail.root@m06>

expr = 1/Sqrt[-h + Sqrt[h^2 + r^2]]*1/Sqrt[h + Sqrt[h^2 + r^2]]; Simplify[expr, h > 0 && r > 0] 1/r Also: Simplify[expr, h \[Element] Reals && r > 0] 1/r Simplify[expr, {h, r} \[Element] Reals] 1/Abs[r] David Park djmpark at comcast.net http://home.comcast.net/~djmpark/ From: Tom D [mailto:tomdickens at att.net] I'm doing a calculation that results in terms of the form 1/ Sqrt[ -h + Sqrt[h^2 + r^2]] * 1/Sqrt[h + Sqrt[h^2 + r^2]] * (other functions) One sees that this simplifies to (other functions)/r. It would helpful to make Mathematica perform this simplification, but I have not been able to get Simplify[] or FullSimplify[] or anything else to do it. How would I be able to do this? Thanks, Tom