double integral problem

*To*: mathgroup at smc.vnet.net*Subject*: [mg112519] double integral problem*From*: Regina <regina.lagrasta at googlemail.com>*Date*: Sat, 18 Sep 2010 07:26:02 -0400 (EDT)

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