Gamma Function Identities

In summary, the person is stuck on a problem and has tried using the third identity, but it did not help. They also attempted to use the first identity, but it did not seem to make a difference. They are seeking help and potentially may need to use an induction argument.
  • #1
binbagsss
1,254
11

Homework Statement



To show:

gammques.png

Homework Equations



gamide.png

The Attempt at a Solution


To be honest, I'm pretty stuck.

I could try to use the third identity:
##\Gamma(-k+\frac{1}{2})=\frac{2\sqrt{\pi}}{2^{-2k}}\frac{\Gamma(-2k)}{\Gamma(-k)} ##

but this doesn't really seem to get me anywhere.

I could also try to use the first identity, by adding and subtracting a 1/2:

##\Gamma(1+(-k-\frac{1}{2}))=(-k-\frac{1}{2})\Gamma(-k-\frac{1}{2})##

Which again doesn't seem to help..

Thanks in advance.
 
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  • #2
binbagsss said:

Homework Statement



To show:

View attachment 211112

Homework Equations



View attachment 211111

The Attempt at a Solution


To be honest, I'm pretty stuck.

I could try to use the third identity:
##\Gamma(-k+\frac{1}{2})=\frac{2\sqrt{\pi}}{2^{-2k}}\frac{\Gamma(-2k)}{\Gamma(-k)} ##

but this doesn't really seem to get me anywhere.

I could also try to use the first identity, by adding and subtracting a 1/2:

##\Gamma(1+(-k-\frac{1}{2}))=(-k-\frac{1}{2})\Gamma(-k-\frac{1}{2})##

Which again doesn't seem to help..
It (the last version) helps a lot if you combine it with an induction argument.
 

1. What is the Gamma function?

The Gamma function, denoted by the Greek letter Γ (gamma), is a mathematical function that extends the concept of factorial to real and complex numbers. It is defined as the integral of the function e^-x x^(s-1) with respect to x, where s is a complex number. In simpler terms, it is a way to interpolate between the factorial function (defined for positive integers) and the real and complex numbers.

2. What are some basic identities of the Gamma function?

Some basic identities of the Gamma function include the reflection formula, the duplication formula, and the multiplication formula. The reflection formula states that Γ(s)Γ(1-s) = π / sin(πs), the duplication formula states that Γ(2s) = 2^(2s-1)Γ(s)Γ(s+1/2), and the multiplication formula states that Γ(s+1) = sΓ(s).

3. How is the Gamma function used in probability and statistics?

The Gamma function is often used in probability and statistics to calculate the probabilities of continuous distributions, such as the chi-square, beta, and exponential distributions. It is also used to calculate moments and other statistical properties of these distributions.

4. What are some useful properties of the Gamma function?

Some useful properties of the Gamma function include its recurrence relation, which states that Γ(s+1) = sΓ(s), and its relationship to the factorial function, which states that Γ(n) = (n-1)! for positive integers n. The Gamma function also has several integral representations, which can be used to evaluate complex and non-standard integrals.

5. How is the Gamma function related to other mathematical functions?

The Gamma function is closely related to other mathematical functions, such as the beta function, which is defined as B(x,y) = Γ(x)Γ(y)/Γ(x+y), and the hypergeometric function, which is defined as 2F1(a,b;c;z) = Σ(n=0 to infinity)(a)_n (b)_n / (c)_n (n!)^2 z^n, where (a)_n is the Pochhammer symbol. The Gamma function also has connections to the Riemann zeta function, the digamma function, and the error function.

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