strange results of integration
- To: mathgroup at yoda.physics.unc.edu
- Subject: strange results of integration
- From: win at wisdom.weizmann.ac.il (Wiener Zvi)
- Date: Fri, 7 Jan 94 12:28:31 +0200
Some strange results (isn't it a bug?):
(* a normal probability distribution *)
In[1]:= p[x_, t_] = 1/(Sqrt[2Pi t])*Exp[-x^2/(2t)];
In[2]:= Integrate[ (Exp[s]-1)*p[s,h], {s,-Infinity, Infinity}]
On::none: Message SeriesData::csa not found.
Out[2]= 0
In[3]:= Integrate[ Exp[s]*p[s,h]-p[s,h], {s,-Infinity, Infinity}]
h/2 1
Out[3]= (-1 + E ) Sqrt[-] Sqrt[h]
h
In[2] and In[3] are actually the same functions but the results are
different!! I also do not understand the Message.
Does anybody knows a simple way to get rid of Sqrt[1/h]*Sqrt[h]
assuming that h is real and positive, without Unprotect and
redefining Sqrt?
Zvi Wiener,
Dept.of Theor. Math.
The Weizmann Inst. of Sc.
Rehovot, 76100, Israel.