Some problems with DSolve and NDSolve

*To*: mathgroup at smc.vnet.net*Subject*: [mg19745] Some problems with DSolve and NDSolve*From*: "Chee Lim Cheung" <cheelc at mbox2.singnet.com.sg>*Date*: Wed, 15 Sep 1999 03:53:01 -0400*Sender*: owner-wri-mathgroup at wolfram.com

Hi MathGroupers, I was somewhat surprised that DSolve is unable to solve the following relatively innocuous system of 1st-order ODEs: DSolve[{2 i1[t] + 2 (i1'[t] - i2'[t]) == 80 t E^(-2t), 4 i2[t] + 2 (i2'[t] - i1'[t]) == 0, i1[0] == 0, i2[0] == 0}, {i1[t],i2[t]}, t] The normally reliable NDSolve also falls down on the following: NDSolve[{2 i1[t] + 2(i1'[t] - i2'[t]) == 80 t E^(-2t), 4 i2[t] + 2(i2'[t] - i1'[t]) == 0, i1[0] == 0, i2[0] == 0}, {i1[t], i2[t]}, {t, 0, 1}] What is wrong? Thanks Chee