What does ! mean in mathematical terms? such as in four fours..?

Question

Okay so i know its equation is this: n!=2(n-1)(n-2)x2x1
and I know it's factorial.
Yes, I understand how to use the equation, but I have never seen "!" in math and I'm wondering if there's actually like a different sign for it, or is it for students with a higher education.

Answer 1

Correct, "!" is the factorial sign and it is actually like this:

n! = n * (n-1) * (n-2) * ... * 3 * 2 * 1

For example, 6! = 6*5*4*3*2*1

It is generally used for calculating probabilities. But of course it is used in many other advanced areas of science.

Answer 2

The shriek is factorial notation and n! = n*(n-1)*(n-2)*....*2*1
actually (where * denotes multiplication), it means the product of all positive integers coming before a number multiplied by the number.
Factorials are mainly used in series. The binomial series, and Taylor, MacLaurin series, and Laurent series.
There's also Sterling's approximation that gives an approximate value for the factorial of a number. Then there's the gamma function which can be used as an integral representation of the facorial.
Hope this clears things up.

Answer 3

In mathematics, ! , the factorial of a natural number n is the product of all positive integers less than or equal to n. This is written as n!

The sequence of factorials (sequence A000142 in OEIS) for n = 0, 1, 2,... starts:

1, 1, 2, 6, 24, 120, 720, 5040, 40320, 362880, 3628800, 39916800, 479001600, 6227020800, 87178291200, 1307674368000, 20922789888000, 355687428096000, 6402373705728000, 121645100408832000, 2432902008176640000, ...
The factorial function is formally defined by:
n!=N(K=1 TO n) k , for all n>or=0.

For example,
5!=5*4*3*2*1=120

The above definition incorporates the convention that:
0!=1.

as an instance of the convention that the product of no numbers at all is 1. This fact for factorials is useful, because

-the recursive relation (n + 1)! = n! × (n + 1) works for n = 0;
-this definition makes many identities in combinatorics valid for zero sizes.
-In particular, the number of arranging or permutations of an empty set is in just one way.
For more pl. visit:
http://en.wikipedia.org/wiki/Factorial

Answer 4

! is the actual symbol used for the factorial function, probably because some mathematicians had a bit of a sense of humor. It is, after all, a rather 'exciting' function, given that it gets big so fast: 1!=1, 2!=2, 3!=6, 4!=24, 5!=120, 6!=720, 7!=5040, 8!=40320, 9!=362880, 10!=3628800, ... etc

Answer 5

! means factorial, yes, but you have the definition wrong:

n! = 1*2*...*(n-1)*n, or n factorial is the product of the integers 1 to n, inclusive.

Factorials show up in probability definitions:
C(m|n) == m!*n!/(m-m)!, read:
The combination of m things taken n at a time is the mth factorial times the nth factorial divided by the (m-n)th factorial.

The combination expression (and therefore, factorials) shows up in the generalization for binomial expansion.

The universal constant, e, is calculated from the infinite series:
e^x=sum(1=x/1!+x^2/2!+x^3/3!+. . . .

Answer 6

i believe it means factorial and you would multiply it by the number 1 less than it, then the number one less than that until that number was 1. 4! = 4*3*2*1=24

Answer 7

It means let your mind come there.