I am really hoping someone can help with this. I am getting two different results when using Integrate in Mathematica using the exact same integrand. When there is a new Kernel, the integral evaluates to one values, and after that, successive running of the Kernal yields a different result running the exact same integrand. Except, after the Kernel has been run more than once, the result doesnt change. The problem is that when you compare the two results, they are not equal.
Why would Mathematica evaluate the exact same integrand to two different results just because of successive running of the Kernel? And more concerning, why are the two results not equal.
Outline of Evaluations below:
In[1]:= Integrate[ (m0 v^3)/(c^2 (1 - v^2/c^2)^(3/2)) + (m0 v)/Sqrt[
1 - v^2/c^2] + (m0 v^3)/(
c0^2 Sqrt[1 - v^2/c^2] (-1 + v^2/c0^2)^(3/2)) - (m0 v^3)/(
c^2 (1 - v^2/c^2)^(3/2) Sqrt[-1 + v^2/c0^2]) - (m0 v)/(
Sqrt[1 - v^2/c^2] Sqrt[-1 + v^2/c0^2]), v ]
Out[1]= (m0 (-2 v^2 + 2 c^2 Sqrt[-1 + v^2/c0^2] -
Sqrt[c^2 - v^2] Sqrt[-c0^2 + v^2]
ArcTan[(c^2 + c0^2 - 2 v^2)/(
2 Sqrt[c^2 - v^2] Sqrt[-c0^2 + v^2])]))/(2 Sqrt[
1 - v^2/c^2] Sqrt[-1 + v^2/c0^2])
In[2]:= Integrate[ (m0 v^3)/(c^2 (1 - v^2/c^2)^(3/2)) + (m0 v)/Sqrt[
1 - v^2/c^2] + (m0 v^3)/(
c0^2 Sqrt[1 - v^2/c^2] (-1 + v^2/c0^2)^(3/2)) - (m0 v^3)/(
c^2 (1 - v^2/c^2)^(3/2) Sqrt[-1 + v^2/c0^2]) - (m0 v)/(
Sqrt[1 - v^2/c^2] Sqrt[-1 + v^2/c0^2]), v ]
Out[2]= (m0 (-v^2 + c^2 Sqrt[-1 + v^2/c0^2] +
Sqrt[c^2 - v^2] Sqrt[-c0^2 + v^2]
ArcTan[Sqrt[-c0^2 + v^2]/Sqrt[c^2 - v^2]]))/(Sqrt[
1 - v^2/c^2] Sqrt[-1 + v^2/c0^2])
In[3]:= (
m0 (-2 v^2 + 2 c^2 Sqrt[-1 + v^2/c0^2] -
Sqrt[c^2 - v^2] Sqrt[-c0^2 + v^2]
ArcTan[(c^2 + c0^2 - 2 v^2)/(
2 Sqrt[c^2 - v^2] Sqrt[-c0^2 + v^2])]))/(
2 Sqrt[1 - v^2/c^2] Sqrt[-1 + v^2/c0^2]) === (
m0 (-v^2 + c^2 Sqrt[-1 + v^2/c0^2] +
Sqrt[c^2 - v^2] Sqrt[-c0^2 + v^2]
ArcTan[Sqrt[-c0^2 + v^2]/Sqrt[c^2 - v^2]]))/(
Sqrt[1 - v^2/c^2] Sqrt[-1 + v^2/c0^2])
Out[3]= False
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