Q.

The integral 1612dxx3(x2+2)2 is equal to                [2023]

1 116-loge4  
2 1112+loge4  
3 116+loge4  
4 1112-loge4  

Ans.

(1)

Let I=1612dxx3(x2+2)2=16121x7(1+2x2)2dx

Let 1+2x2=p  -4x3dx=dp  dxx3=-14dp

I=-433/2dp4(p-1)2·p2

=-433/2(p-1)2dp4p2=-33/2p2+1-2pp2dp

=-33/2(1+1p2-2p)dp=-[p-1p-2logp]33/2

=-[{56-2loge(32)}-{83-2loge3}]

=-[2loge2-116]=116-loge22=116-loge4