Yup. I managed to get it too.
Oh. I guess qn should give a hint first like use by parts followed
by substitution first or sumthing like that.
Cos, as above, I use substitution first, then by parts, ans is 2/3
(1 + x)^6 +c
Ans is vastly different from the other ans (1/2)X( X^2 + 1)^0.5 +
0.5ln (X + (X^2 +1)^0.5) + C which use by parts first then
substitution.
