 
 
 
The Ci command takes as argument a complex number.
Ci returns the value of the cosine integral function Ci at
the point, where 
| Ci(x) = | ∫ | 
 | 
 | dt = ln(t) + γ + | ∫ | 
 | 
 | dt | 
 
This satisfies Ci(0) = −∞, Ci(−∞) = iπ and Ci(+∞)
= 0.
Input:
Output:
Input:
Output:
Input:
Output:
 
 
