Failure to Evaluate?

*To*: mathgroup at smc.vnet.net*Subject*: [mg49842] Failure to Evaluate?*From*: "Scott Guthery" <sguthery at mobile-mind.com>*Date*: Tue, 3 Aug 2004 01:11:14 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

f:=Function[#1^2/#1+1] g:=Function[#1^4+7] h:=D[f]/D[g] h[1] Gives ((#1^2/#1)+1 &)/(#1^4+7 &)[1] Why doesn't it evaluate by setting #1 to 1 to get 1/4? h/.#1->1//N sets #1 to 1 and gives (1 1 + 1 &)/(1 + 7 &) but still doesn't evaluate to 1/4. What gives? What's the Right Stuff? Thanks for any insight. Cheers, Scott

**Follow-Ups**:**Re: Failure to Evaluate?***From:*Andrzej Kozlowski <akoz@mimuw.edu.pl>

**Re: Failure to Evaluate?***From:*DrBob <drbob@bigfoot.com>