Tính \[\smallint cot5xdx\]

\[\frac{{ - 1}}{3}ln\left| {cos3x} \right| + C\]

\[\frac{1}{3}ln\left| {cos5x} \right| + C\]

\[ - \frac{1}{3}ln\left| {\sin 3x} \right| + C\]

\[\frac{1}{5}ln\left| {\sin 5x} \right| + C\]