why 0!=1 ? Why not 0?

Question

anonymous · Answer

my math teacher described it in terms of the way that factorials are used in permutations and combinations. there is only one way to choose any number of options from 0 options. the actual math is a lot more complicated, but that's a simpler way to remember/understand

anonymous · Answer

where are you from? @cerezas

anonymous · Answer

as in.... hometown, school, what?

cwrw238 · Answer

take the formula
nCr =    n!
           ----
           n-r! r!

if n = 2 and r = 2

then 2C2 =  2!               21
                 ----    =     ----  = 1
              2-2! 2!          0! 2!

so 0! is taken to be 0

cwrw238 · Answer

i guess it makes sense because there is only one way of having nothing, right?

anonymous · Answer

^that's what I just said. @cwrw238

experimentx · Answer

Interesting http://mathforum.org/dr.math/faq/faq.0factorial.html

cwrw238 · Answer

yeah ok - i wqs just engrossed in my typing!

anonymous · Answer

fair enough :D

anonymous · Answer

@ademm37 i just graduated from Miami palmetto Senior high :) going to caltech this fall

anonymous · Answer

0!=1 I think that's an acceptance.

anonymous · Answer

everybody thanks