$$\displaystyle\int{ \frac{ \sqrt{ { x }^{ 2 } + { 3 }^{ 2 } } }{ { x }^{ 4 } } }d x$$
$-\frac{\left(x^{2}+9\right)^{\frac{3}{2}}}{27x^{3}}+С$
$\frac{\sqrt{x^{2}+9}}{x^{4}}$
