Re: (Not trivial) Definite Integration of a rational function

*To*: mathgroup at smc.vnet.net*Subject*: [mg74787] Re: (Not trivial) Definite Integration of a rational function*From*: Bhuvanesh <lalu_bhatt at yahoo.com>*Date*: Thu, 5 Apr 2007 04:10:48 -0400 (EDT)*Organization*: The Math Forum

Offhand I'm not sure why this failed in 5.2, but it works in the development version: In[1]:= Integrate[(2*x)/((x + 1)*(x^3 + 3*x^2 + 2*x + 1)), {x, 0, Infinity}] //Timing //InputForm Out[1]//InputForm= {0.85, -2*RootSum[1 + 2*#1 + 3*#1^2 + #1^3 & , (Log[-#1] + 2*Log[-#1]*#1 + Log[-#1]*#1^2)/(2 + 6*#1 + 3*#1^2) & ]} In[2]:= N[Last[%], 20] -20 Out[2]= 0.37121697526024703447 + 0. 10 I Bhuvanesh, Wolfram Research.