Chi
 |
 |
The hyperbolic cosine integral, often called the "Chi function" for short, is defined by
 |
(1)
|
where 
is the Euler-Mascheroni
constant. The function is given by the Wolfram
Language command CoshIntegral[z].
The Chi function has a unique real root at 
(OEIS A133746).
The derivative of 
is
 |
(2)
|
and the integral is
 |
(3)
|
Contact the MathWorld Team
Soldner's constant
