(bottom derivative of top - top derivative of bottom)/bottom squared
4 [ (1-e^x)e^x - e^x (-e^x) ] / (1-e^x)^2
4 [ e^x -e^2x + e^2x ]/(1-e^x)^2
4 e^x /(1-e^x^2)
interesting, check carefully
f'(x) of
f(x)= 4e^x/1-e^x
2 answers
4 e^x /(1-e^x^2)^2