# Can anybody see a mathematical relationship here?

1. May 23, 2005

### eNathan

Hi. I was playing with the square of numbers for a few hours, and I can up with this set of numbers, can anybody show me a relationship?

P X D
______
2 2 2
_______
3 3 6
_______
4 4 24
_______
5 5 120
_______

I cannot see a relationship :surprised But there has to be. Any help?

--eNathan (3.14)

2. May 23, 2005

### Curious3141

What exactly were you playing around with ? That'll help us to explain the relationship better.

Anyway, $$2 ! = 2, 3 ! = 6, 4 ! = 24, 5 ! = 120$$, the last column appears to comprise factorials of the identical first two column numbers.

3. May 23, 2005

### eNathan

What do all the '!' mean? I though != is innequality <>

4. May 23, 2005

### Curious3141

No that's computer speak (for example, C programming uses that).

'!' in Maths is factorial. $$n! = 1.2.3....(n-1)(n)$$, the sequential product of all natural numbers less than or equal to n. It is only defined for nonnegative integers, with 0! = 1 (by definition). (There is an extension of factorial for non-integers called the gamma function, but you don't have to worry about that for now).

OK, so what were you doing, maybe I or someone else can help you understand the pattern.

Last edited: May 24, 2005
5. May 24, 2005

### uart

n, n, n! Other than that what were you looking for?

6. May 24, 2005

### eNathan

I am asking, givin this set

P X D
______
2 2 2
_______
3 3 6
_______
4 4 24
_______
5 5 120

I am saying, is there any way to mathematicly manipulate P, and X to get the value of D? For the first one, I guess you could do P / X * P = D, but that would not work for the second one. For the second one you could do P + X = D, but that would not work for the third one. And I dont even know how you can mathematicly manipulate 4 and 4 to get 24, I suppose (PX + (2X)) but that makes no sense. I will try to explain how I got these numbers when I have the time I am at school ATM.

7. May 24, 2005

### matt grime

The answer, from that set, is D=P! and is independent of X (though as X=P that is debatable).

I think everyone wishses you to state what P, X and D are.

8. May 24, 2005

### uart

Yes of course. As already pointed out D=factorial(P) and X is just redundant.

9. May 24, 2005