Primitive of Cotangent of a x/Examples/Half x

Example of Use of Primitive of $\cot a x$

 * $\ds \int \cot \dfrac x 2 \rd x = 2 \ln \size {\sin \dfrac 1 2} + C$

Proof
From Primitive of $\cot a x$:

Then:

The result follows by setting $a = \dfrac 1 2$.

Proof

 * : $\text {II}$. Calculus: Exercises $\text {XIV}$: $3$.