Posted by tiffanie robinson on Wednesday, August 31, 2005 at 6:00pm.
i just need help with factorials
I assume you know what a factorial is:
1! = 1
2! = 1x2 = 2
3! = 1x2x3 = 6
N! = 1x2x3x...x(N-1)xN
They occur often in probability theory.
Please ask a more specific question about factorials. I have no idea what else to tell you.
what is the explicit formula for the nth factorial? is there one without n*(n-1)*(n-2) and so forth?
No, drwls is correct; N! = 1*2*3...*N.
However, when using factorials, short-cuts and simplifications will often be present. For example, the formula for counting the number of ways one can deal two cards from a standard 52-card deck is:
52! / 2!(52-2)!
Well, calculating 52! by itself is an onerous task. However, we can simplify. 52!/50! cancels to 51*52, and 2! is simply 1*2=2. So, the answer is 51*52/2 = 1326.
I hope this helps
Why is 0! equal to one? write back asap!!
-concerned student seeking help
Answer This Question
More Related Questions
- math - what is the factorial of a negative number? The factorial function has ...
- Algebra (factorial) - Evaluate gcd(19!+19,20!+19). Details and assumptions The ...
- Math - -5,-3,-1,1,3,5 If a and b are different integers chosen from the list ...
- math - Find the sum of all positive integers m such that 2^m can be expressed as...
- 12th grade Data - In this sequence, tk is a factorial number, often written k!. ...
- math - Simplify: 2/1! - 3/2! + 4/3! - 5/4! + ... + 2010/2009! - 2011/2010!, ...
- Algebra 1 - Can you please check my work and help me with the parts that I don't...
- math - WAT IS 12 FACTORIAL
- math - Evaluate the factorial. 5!
- math - what is expression 5 factorial equal