Ci( z )
The cosine integral of z in SageMath. Alias of cos_integral. Defined by
\[ \operatorname{Ci} (z) = \gamma + \ln(z) + \int_0^z du \: \frac{ \cos(u) - 1 }{ u } \]where γ is euler_gamma.
Plot on the real axis:
Series expansion about first root:
Special values:
Related functions: cos_integral
Function category: exponential integrals sagemath-docs