Re: double integral problem

*To*: mathgroup at smc.vnet.net*Subject*: [mg112554] Re: double integral problem*From*: Bob Hanlon <hanlonr at cox.net>*Date*: Sun, 19 Sep 2010 05:41:02 -0400 (EDT)

You have not defined the variable a so numeric techniques will not work. Manipulate[ NIntegrate[ Exp[-a/(4 x) - 4 x], {Q, 0, 1}, {x, 0, Q}], {a, 0, 5, Appearance -> "Labeled"}] Plot[NIntegrate[ Exp[-a/(4 x) - 4 x], {Q, 0, 1}, {x, 0, Q}], {a, 0, 5}] Bob Hanlon ---- Regina <regina.lagrasta at googlemail.com> wrote: ============= hi there, im trying to evaluate the following double integral: N[Integrate[Integrate[Exp[-a/(4 x) - 4 x], {x, 0, Q}], {Q, 0, 1}]] and set a to 1 or some other non-zero number. but for some reason, mathematica only gives me error messages. what am i doing wrong? best. regina