Make the substitution:
x=\tan(u),\to\frac{dx}{du}=\frac{1}{\cos^{2}u}
Thus, we get:
dx=\frac{du}{\cos^{2}(u)}
and insertion in your integral yields:
\int\frac{arctan(x)}{(1+x^{2})^{\frac{3}{2}}}=\int{u}\cos(u)du
#3
hadi amiri 4
98
1
your solution seems nice
honestly i thought it is a hard one,becouse i picked it form "A coures of pure mathematics"