suivant: The function : Zeta
monter: Real numbers
précédent: The function : Beta
Table des matières
Index
Derivatives of the DiGamma fonction : Psi
Psi takes as arguments a real a and an integer n (by
default n = 0).
Psi returns the value of the n-th derivative of the DiGamma function
at x = a, where the DiGamma fonction is the first derivative
of
ln((x)). This function is used to evaluated sums of
rational functions having poles at integers.
Input :
Psi(3,1)
Output :
pi^
2/6-5/4
If n=0, you may use Psi(a) instead of Psi(a,0)
to compute the value of the DiGamma fonction at x = a.
Input :
Psi(3)
Output :
Psi(1)+3/2
Input :
evalf(Psi(3))
Output :
.922784335098
giac documentation written by Renée De Graeve and Bernard Parisse