How to Prove Stirling's Formula for ln(n!) ?

In summary, Stirling's Formula is a mathematical formula that approximates the factorial of a large number n. It was first derived by Scottish mathematician James Stirling in the 18th century using the method of asymptotic expansions. The formula is significant because it provides a quick and accurate approximation of factorials for large numbers, with applications in fields such as statistics, physics, and computer science. However, it is only accurate for large values of n and does not work well for negative values or non-integer numbers.
  • #1
rcianfar
1
0

Homework Statement



Prove that ln(n!) = nln(n) - n + ln(2*pi*n)/2 for large n.


Homework Equations



I've been working on the proof but I just can't get it. Can anyone help me out?

The Attempt at a Solution

 
Physics news on Phys.org
  • #2
You can find the proof at many places on the web.
 

FAQ: How to Prove Stirling's Formula for ln(n!) ?

What is Stirling's Formula?

Stirling's Formula is a mathematical formula that approximates the factorial of a large number n. It is expressed as n! ≈ √2πn (n/e)^n.

How is Stirling's Formula derived?

Stirling's Formula was first derived by Scottish mathematician James Stirling in the 18th century. He used the method of asymptotic expansions to approximate the factorial function when n is large.

What is the significance of Stirling's Formula?

Stirling's Formula is significant because it provides a quick and accurate approximation of factorials for large numbers, which can be difficult to calculate directly. It has many applications in fields such as statistics, physics, and computer science.

Are there any limitations to using Stirling's Formula?

Stirling's Formula is only accurate for large values of n. As n gets smaller, the approximation becomes less accurate. It also does not work well for negative values of n.

Can Stirling's Formula be used to calculate the factorial of non-integer numbers?

No, Stirling's Formula is only valid for positive integers. It cannot be used to approximate the factorial of non-integer numbers.

Similar threads

Back
Top