∫ex1−x1+x22dx is
ex1+x22+c
−xex1+x22+c
ex(1−x)1+x22+c
ex1+x2+c
∫ex1−x1+x22dx=∫ex1+x2−2x1+x22dx=∫ex11+x2−2x1+x22dx=11+x2ex+∫ex2x1+x22dx−∫ex2x1+x22dx+C=ex1+x2+C