SAT - Math - Complex Numbers
For i=√-1, what is the sum (7 3i) (-8 9i)?
can you please say me the reason why 1 is not a prime number as well as composite number? Thank you (more)
we can't say 1 as prime as well as composite.
Historically there was a time when 1 was considered a prime number,
But there is a fundamental theorem in Arithmetic which says that "Every positive whole number can be written as a UNIQUE product of primes"
So for example 6 = 2 x 3 (Both two and 3 are primes) (this is unique)
if we considered 1 as a prime
6 = 1 x 2 x 3 or 1 x 1 x 2 x 3 (Does not remain unique)
hence to keep this fundamental theorem intact, 1 is not considered a prime.
But this a good question.
1 is also not a composite number, because it cannot be split into product of two or more primes.