Question

integrate (e^tan^-x)/1+x^2

Answer 1

integration of e^tan^-1x/(1+x^2)
let
tan^-1x =z
now differentiate
dx/(1+x^2)=dz
dx =(1+x^2)dz
put dx =(1+x^2)dz

now will be
integration of e^z.dz
hence integration of this =e^z +c

hence e^tan^-1x + c is integrant of above