I=∫x2−1x32x4−2x2+1dx equal to
2x4−2x2+1+C
2x4−2x2+1x3+C
2x4−2x2+1x+C
2x4−2x2+12x2+C
I=∫1/x3−1/x52−2/x2+1/x4dx
put 2−2x2+1x4=t2⇒4x3+4x5dx=2tdt
∴ I=12∫tdtt=12t+C=122−2x2+1x4+C=2x4−2x2+12x2+C