Posted by John on Saturday, October 2, 2010 at 7:23pm.
I'm trying to figure out the generalized form of the Gaussian n-factorial (n!) formula.
I keep seeing n!= n(n+1)/2 but that's not working.
For example: 5!= 120 but 5(6)/2 or 6(5/2) is 15; a far cry from 120. I don't understand what I'm doing wrong; distributing gives (n^2+n)/2 which is incorrect.
Also the example I saw as the supposed true story used 1-100 and showed it as 101(100/2) = 5050.
What am I missing here?
- math (Gaussian n! formula) - bobpursley, Saturday, October 2, 2010 at 7:35pm
I dont know where you got that formula, it is obviously wrong.
2!=2*1 which does not equal 2*3/2
- math (Gaussian n! formula) - MathMate, Saturday, October 2, 2010 at 7:38pm
There must be a confusion somewhere.
Gauss as a small boy in school was told by his teacher to add numbers from 1 to 100, after which he can play outside. While everyone else was still adding away, he went out and played after about 2 minutes. His teacher was about to punish him when he told the teacher he finished!
When asked how he did it, he answered:
Write the numbers 1-100 and 100-1 one on top of the other and add vertically. We have 100 sums of 101 for two rows, so the sum for one row is 101*100/2=5050.
So probably this 1-100 = 5050 formula became the famous Gauss formula, but not for factorial.
If you are looking for an approximation to the factorial function, i.e. f(n)=n! (approximately), use the Stirling formula.
lim n->∞ n!=√(2πn)(n/e)n.
Answer this Question
More Related Questions
- Math - How would I determine if a set of numbers if Gaussian or non Gaussian?
- math (cant figure it out) - How to find the surface area of a cylinder with a ...
- physics2 - A Gaussian surface encloses two charges. The total electric flux ...
- Math - For the following data... 1. Provide evidence as to whether this data set...
- Physics - A parallel plate capacitor has a rectangular plates with length 5cm ...
- factorial help!!! - i just need help with factorials I assume you know what a ...
- gaussian elimination - 4. Solve the following linear system using Gaussian ...
- Chemistry - the formula H2O2 is an example of 1.molecular formula 2. an ...
- Physics - A long insulating wire has a uniform charge density 7nC/m and r=3m ...
- algebra - What is the slope of a line through (-5,2) and (6,7) in the standard(x...