Factorial of 0 Proof:
since we know that

where n belongs to positive integer
Examples.
Now we will prove that 0!=1 is equal to one.
As

Put
Hence factorial of 0 is equal to 1
Why it is not possible to have a negative factorial ?
Is factorial define for nagative numbers?
why can not have a negative factorial?
why no negative factorial?
for negative integers
put
(negative).(negative).(negative).(negative)…………(negative).(negative)……
Hence prove that negative factorial does not exist.
Power zero is equal to ?
power zero is equal to 1
what does zero power mean
Anything power zero is equal to
put in eq(a)
dividing on both sides.
hence any number power zero is equal to 1