Gamma Function

(x) = e^-t t^(x-1) dt
(x) = r^x e^-rt t^(x-1) dt
(x) = 2 e^{(-t^2)} t^(2x-1) dt
( (x)(y) ) / ( (x) + (y) ) = Beta(x,y)
(x+1) = x (x)
(x+1) = x!
(0+) = +
(1/2) = (PI)
(z) (1-z) = PI csc(PI z) '(1) = - gamma (Euler's constant = 0.577215...)

Gamma '(x) = Gamma (x) lim (n--> inf ) [ ln(n) - sum _(k=0..n-1) 1/(x+k) ]

Function Expansions

Gamma (x+1) = lim _(k-->) k^x 1*2*3*..*k
(x+1)(x+2)*..*(x+k)

Stirling's Asymptotic Series
Gamma (x+1) = sqrt (2PIx) x^x e^-x { 1 + 1/(12x) + 1/(288 x²) - 139/(51840 x³) - 571/(2488320 x⁴) + 163879/(209018880 x⁵) + 5246819/(75246796800 x⁶) - 534703531/(902961561600 x⁷) - ...}
(this is only an approximation, see note.)

Incomplete Gamma Functions:
(x, a) = e^-t t^(x-1) dt
(x, a) = e^-t t^(x-1) dt

(x, a) + (x, a) = (x)

(x) = e^-t t^(x-1) dt	(x) = r^x e^-rt t^(x-1) dt
(x) = 2 e^{(-t^2)} t^(2x-1) dt	( (x)(y) ) / ( (x) + (y) ) = Beta(x,y)
(x+1) = x (x)	(x+1) = x!
(0+) = +	(1/2) = (PI)
(z) (1-z) = PI csc(PI z)	'(1) = - gamma (Euler's constant = 0.577215...)
'(x) = (x) lim (n-->) [ ln(n) - _(k=0..n-1) 1/(x+k) ]

Math2.org Math Tables: Gamma Function