Question

\[\int\limits_{1}^{In3}(e^x-e^{3x})/(1+e^x)\]

Answer 1

\[\int\limits_{1}^{In3}(e^x-e^{3x})/(1+e^x)\]

Answer 2

simplify..

Answer 3

e^x (1+e^x)=e^x+e^2x

Answer 4

its o not e^x+e^2x, but e^x-e^3

Answer 5

if e^x = t and e^xdx = dt
you got:
\[(1-t ^{2})dt/1+t = 1-t dt\]
rest it's easy

Answer 6

now the integral should be easier...