Re: Re: Re: Trouble with Integrate

• To: mathgroup at smc.vnet.net
• Subject: [mg39370] Re: [mg39316] Re: [mg39268] Re: [mg39264] Trouble with Integrate
• From: Vladimir Bondarenko <vvb at mail.strace.net>
• Date: Thu, 13 Feb 2003 04:51:59 -0500 (EST)
• References: <200302070807.DAA26439@smc.vnet.net> <200302110941.EAA26028@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

```Marko Vojinovic <vojinovi at panet.co.yu> wrote on Tue, 11 Feb 2003 04:41:28

MV> Let

MV> g = Sqrt[1+x^(2a)]-x^a

MV> where if we put the parameter a to be 2 we recover the original function, f.
MV> Now,

MV> Integrate[g,{x,0,Infinity}] /. a->2

In[1] := Integrate[Sqrt[1 + x^(2a)] - x^a, {x, 0, Infinity}] /. a -> 2/3

Out[1] = -(Gamma[-5/4]*Gamma[7/4])/(2*Sqrt[Pi])   (*  <- INVALID  *)

In[2] := N[%]

Out[2] = -1.01666

Actually this integral, obviously, diverges to the plus infinity.

In[3] := N[Integrate[Sqrt[1 + x^(2a)] - x^a, {x, 0, 10^10}] /. a -> 2/3]

Out[3] = 3232.

Best wishes,

Mathematical and Production Director
Symbolic Testing Group

Web  :  Self-censorship: Steve will edit it out all the same ;-)

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```

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