Naleznìte primitivní funkce:
$$
\int \frac{1}{1+\sqrt{x^2+2x+2}} \dx,     \qquad      
\int \frac{1}{\sqrt{-x^2 + 4x - 3}}, \qquad \\
$$
$$
\int \frac{1}{\root 3 \of {(x-1)^2(x+1)}}, \qquad
\int \frac{1}{1 + \exp{(x/2)} +\exp{(x/3)} + \exp{(x/6)}} \dx.
$$
