Question

what does ( ! ) mean in mathematics?

Answer 1

! Means factorial of example 4!=4×3×2×1

Answer 2

it means factorial.
1! = 1
2! = 2×1
3! = 3×2×1
4! = 4×3×2×1
and so on......
★ NOTE :- 0! is also = 1
(and all these values are calculated by gamma function, which u will study in engineering maths).