∫(1+x)2x(1+x2) dx
(4)
Ans. logx+2tan-1x+C
Explanation
∫(1+x)2x(1+x2)dx=∫(1+x2)+2xx(1+x2)dx
=∫(1x+2·11+x2)dx
=∫1xdx+∫21+x2dx
=logx+2tan-1x+C