# Any idea for this integral?

I'm trying to solve this integral with respect to a and b two positive reals. I think it's hopeless to find a closed form solution nevertheless if anyone has an idea to approximate analytically its true value this would be well enough for my needs :

$$\int_\mathbb{R} \frac{e^{-\frac{x^2}{2}}}{1+e^{-a.x-b}}dx$$

Best regards

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what is $-a.x-b$ ? –  Block Jeong Dec 2 '13 at 14:07
I think that was a rogue dot. –  Doc Dec 2 '13 at 14:14
In England, one may write $a.x$ instead of $a\cdot x$. Is TheBridge from England? –  GEdgar Dec 2 '13 at 14:23
It might help to tag this as numerical analysis as well. –  Doc Dec 2 '13 at 14:35
@ Doc, Block Jeong : the dot stands simply for scalar multiplication, and "non" I'm not english ;-). I tagged the question in numerical-methods, thank's for pointing that out. Best regards –  TheBridge Dec 2 '13 at 14:54