Bug in 2-D integration?

 Bug in 2 D integration?
Integrate[
 1/(1 + z^2) Exp[-r^2/(1 + z^2)] r
 , {r, 0, Infinity}
 , {z, -a, a}
 ]

0

Integrate[
 1/(1 + z^2) Exp[-r^2/(1 + z^2)] r
 , {z, -a, a}
 , {r, 0, Infinity}
 ]

a

Just changing the order of integration limits changes the result. The correct answer is a. Parameter a is otherwise undefined. This is in version Mathematica 10.4.0.0

Let’s block ads! (Why?)

Recent Questions – Mathematica Stack Exchange