Question

what is factorial in maths define.

Answer 1

the product of all the positive no. below and equal to the chosen no. is called as factorial

example:- suppose we have to find factorial of 5

       then all positive no.below 5 and including 5 are 1,2,3,4,5

the product is =1×2×3×4×5=120

hence the factorial 5 value is 120

exception:- the value of factorial 0 is 1.

Answer 2

the factorial is a reverse product n no to 1
the n no is 5 so the factorial of 5 is
5×5×3×2×1
=120