       RE: Strange results from Integrate

• To: mathgroup at smc.vnet.net
• Subject: [mg16065] RE: [mg16022] Strange results from Integrate
• From: "Ersek, Ted R" <ErsekTR at navair.navy.mil>
• Date: Tue, 23 Feb 1999 03:45:20 -0500
• Sender: owner-wri-mathgroup at wolfram.com

```Sergio Terrazas:
Reported a problem with Integrate.
______________________

I think he found a problem, but don't agree with some of the results he
posted.  I am using Version 3.0.1 with a Windows 95.  I get the results
below.

Out, Out, Out, Out, and Out below show the right answers.
______________________

In:=
F[x_]=Integrate[Exp[-20(x-125/10)],x]
Out=
-E^(250 - 20*x)/20

In:=
F[Infinity]-F[126/10]
Out=
1/(20*E^2)

In:=
Integrate[Exp[-20(x-125/10)],{x,126/10,Infinity}]
Out=
1/(20*E^2)

In:=
N[%]
Out=
0.006766764161830635

In:=
NIntegrate[Exp[-20(x-12.5)],{x,12.6,Infinity}]
Out=
0.006766764161830801
__________________

Out, Out, and Out below show wrong answers.  I can't explain how it

In:=
Integrate[Exp[-20(x-12.5)],{x,126/10,Infinity}]
Out=
0.

In:=
Integrate[Exp[-20(x-125/10)],{x,12.6,Infinity}]
Out=
3.259257562135177*^91

In:=
Integrate[Exp[-20(x-12.5)],{x,12.6,Infinity}]
Out=
3.259257562135177*^91

___________________
Regards,
Ted Ersek

```

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