Hello, I am desperately trying to evaluate the following integral for several days now:
Integral[(1/(1+Exp[-x]))*Log[1/(1+Exp[-(x*w+b)])],{x,-Infinity,Infinity}]
I can't get Mathematica to do it; so I tried - at some point - this:
Integrate[(1/(1 + Exp[-x]))*Log[1/(1 + Exp[-x])], x]
That results in a formula, but it doesn't seem to make any sense?! It returns:
https://gyazo.com/8ebda5752271450bbcf73067974f84a8
(I can't get Mathematica to copy anything to clipboard)
This contains Log[-Exp[x]]
which can't exist since Exp[] is always positive?!
Can someone please help,
Carlo Wood