Answer:
y=ln(x/(1-x))
Explanation:
y=e^x/(1+e^x)
Cross multiply
y(1+e^x)=e^x
Distribute
y+ye^x=e^x
Put anything with x on with side and everything without x on opposing side:
y=e^x-ye^x
Factor right hand side
y=(1-y)e^x
Divide both sides by (1-y)
y/(1-y)=e^x
Use natural log.
ln(y/(1-y))=x
The inverse is
y=ln(x/(1-x))