A problem with an integral

*To*: mathgroup at smc.vnet.net*Subject*: [mg32801] A problem with an integral*From*: WhoamI <lushstring at yahoo.com>*Date*: Tue, 12 Feb 2002 06:23:59 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

Hi everybody, I have a problem with the next integral Integrate[Sin[x y],{x,0,1},{y,0,x}] that after expanding and factoring yields: \!\(1\/4\ \((EulerGamma - 2\ CosIntegral[1])\)\) and evaluating this I have -0.024398 To be sure about the answer I taked it other way: Integrate[ TrigFactor[Integrate[Sin[x y], {y, 0, x}]] , {x, 0, 1}] which yields \!\(1\/2\ \((EulerGamma - CosIntegral[1])\)\) and evaluating this I have 0.119906 Since I evaluated this integrals not numerically I don't understand why the answers are different. Is there something wrong with my code?. I would thanks a lot for your answers... Cesar Guerra Secc. Fisica PUCP-Lima __________________________________________________ Do You Yahoo!? Send FREE Valentine eCards with Yahoo! Greetings! http://greetings.yahoo.com