Primitive of Sine Integral Function

Theorem

 * $\ds \int \map \Si x \rd x = x \map \Si x + \cos x + C$

where $\Si$ denotes the sine integral function.

Proof
By Derivative of Sine Integral Function, we have:


 * $\map {\dfrac \d {\d x} } {\map \Si x} = \dfrac {\sin x} x$

So: