`(x^(3)sin(tan^(-1)x^(4)))/(1+x^(8))`

Explanation

`int(x^(3)sin(tan^(-1)x^(4)))/(1+x^(8))dx" माना "tan^(-1)x^(4)=t`
`" "rArr (4x^(3))/(1+x^(8))dx=dt`
`=intsin t (dt)/(4)" "rArr (x^(3))/(1+x^(8))dx=(dt)/(4)`
`=-(1)/(4)cos t+c =-(1)/(4)cos(tan^(-1)x^(4))+c`