Re: integration frustration

*To*: mathgroup at smc.vnet.net*Subject*: [mg91927] Re: integration frustration*From*: "David Park" <djmpark at comcast.net>*Date*: Sat, 13 Sep 2008 05:54:04 -0400 (EDT)*References*: <gadcke$riv$1@smc.vnet.net>

Mathematica won't perform the integration unless f is defined. However, I think your statement is true provided f is a monotonically increasing function. -- David Park djmpark at comcast.net http://home.comcast.net/~djmpark/ "Replacedwings" <cabaret_voltaire at hotmail.com> wrote in message news:gadcke$riv$1 at smc.vnet.net... > Dear All, > > I have a question about a particular integral: > > > i[r]= Integrate[(L-z)(f[Sqrt[z^2+r^2]] -f[z]),{z,0,L}] > > > Assumptions->f[0]==0, f[r]>0 if r>0. > > Is i[r]>=0 for all r? > > Any Ideas? > > Help! > > TIA, > > Chris >