now, 1 is neither a prime nor a composite number.
but until about 100 years ago, 1 used to be a prime.
why some mathematicians considered 1 as a prime?
This video explains the reason and background through math history.
#one #primenumber #history

why 1 was considered as a prime before?
the detail record of 1 as a prime
the reason why 1 was considered as a prime
definition of prime number
math history of prime number