Definition:Cosine Integral Function

Definition
The cosine integral function is the real function defined as:


 * $\Ci: \openint 0 \to \to \R$:


 * $\map \Ci x = -\displaystyle \int_{t \mathop = x}^{t \mathop \to +\infty} \frac {\cos t} t \rd t$

Graph

 * CiFunction.png

Also see

 * Characterization of Cosine Integral Function