Re: Assigning (really dumb question)

*To*: mathgroup at smc.vnet.net*Subject*: [mg60999] Re: [mg60988] Assigning (really dumb question)*From*: Chris Chiasson <chris.chiasson at gmail.com>*Date*: Fri, 7 Oct 2005 03:37:44 -0400 (EDT)*References*: <200510060808.EAA08545@smc.vnet.net>*Reply-to*: Chris Chiasson <chris.chiasson at gmail.com>*Sender*: owner-wri-mathgroup at wolfram.com

Try leaving off the q -> On 10/6/05, vjp2.at at at.biostrategist.dot.dot.com <vjp2.at at at.biostrategist.dot.dot.com> wrote: > What the heck am I doing wrong? I've been away from Mathematica for a while. > > I can't get it to evaluate the expressions at the solved values. > > I feel so stupid. > > r[q_] := 1800 q - .006 q^2 > c[q_] := 12100000 + 800 q + .004 q ^2 > > qa = Solve[ D[ r[q]-c[q] , q] == 0, q] > r[q] /. q -> qa > c[q] /. q -> qa > r[q]-c[q] /. q -> qa > D[r[q],q] /. q -> qa > D[c[q],q] /. q -> qa > > qm = Solve[ c[q]/q - D[c[q] , q] == 0, q] [[2]] > r[qm] /. q -> qm > c[qm] /. q -> qm > r[qm]-c[qm] /. q -> qm > D[r[q],q] /. q -> qm > D[c[q],q] /. q -> qm > > > (PS, a while back I was asking how to fix DOS 2.2.2 when it wasn't > doing graphics and I was told it was no longer supported. Well, 2yrs > later, dumbo me, realised I just had to cd into the math directory and > all was fine.) > > > - = - > Vasos-Peter John Panagiotopoulos II, Columbia'81+, Bio$trategist > BachMozart ReaganQuayle EvrytanoKastorian > http://ourworld.compuserve.com/homepages/vjp2/vasos.htm > ---{Nothing herein constitutes advice. Everything fully disclaimed.}--- > [Homeland Security means private firearms not lazy obstructive guards] > [Fooey on GIU,{MS,X}Windows 4 Bimbos] [Cigar smoke belongs in veg food group] > > -- Chris Chiasson http://chrischiasson.com/contact/chris_chiasson

**References**:**Assigning (really dumb question)***From:*vjp2.at@at.BioStrategist.dot.dot.com