once more integrate
- To: mathgroup at smc.vnet.net
- Subject: [mg20735] once more integrate
- From: Wolfgang Schadow <schadow at netcom.ca>
- Date: Wed, 10 Nov 1999 00:17:47 -0500
- Sender: owner-wri-mathgroup at wolfram.com
Hi,
here is one more integral that is not calculated correct:
In[4]:= Integrate[1/x^2,{x,-2,2}]
Out[4]= Infinity (correct)
In[5]:= Integrate[1/x^2,{x,-Abs[a],2}] /. a -> 2
Out[5]= -1 (not correct)
In[6]:= Integrate[1/x^2,{x,-Abs[a],2}]
1 1
Out[6]= -(-) - ------
2 Abs[a]
In[7]:= Integrate[1/x^2,{x,-a,a}]
-2
Integrate::idiv: Integral of x does not converge on {-a, a}.
-2
Out[7]= Integrate[x , {x, -a, a}]
In the first case Mathematica gives the corrcet answer, in the
second case it overlooks the singularity. In the third case the
answer is at least not wrong.
Wolfgang Schadow
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