how can I solve a function Erfc

*To*: mathgroup at smc.vnet.net*Subject*: [mg48396] how can I solve a function Erfc*From*: montgermont.aude at ec-lille.fr (aude)*Date*: Fri, 28 May 2004 00:50:23 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

Hi, I have to solve this function: Erfc[L/(4*(Dg*t)^(1/2))]= 0.9 Dg is constant. Dg=5*10^5 I want to plot t as a function of L. thanks. aude