Finding prime number with Square root

Finding prime number with Square root is it possible? Got it in my programming assignment

 

see this:
http://en.wikipedia.org/wiki/Prime_number#Finding_prime_numbers
look at the 7th line

 

nw solved it already hahahaha I can't do that in C++ ln functions...=="

 

No prime number needs to be a whole number. If sqrt(n) is a whole number m, then n = m². n, therefore is not a prime number. m doesn't have to be prime number because m can be any numbers, prime or not prime, real or imaginary to satisfy the equation m² = n or m = sqrt(n).

 

Wait iiimj4everiii, it won't work if someone input n = 10, 8, 12, 14, 20...

 

You cannot use the square root to determine if it's a prime number or not. The square root only only used for the limit number factor of the number that the person inputted.

For example:

input = 100
10 = sqrt of 100

for(int i=2; i<=10; i++)
{
// check if i is one of the factors of the input number.
}



THIS IS THE CORRECT WAY.

 

again: No prime number needs to be a whole number. If sqrt(n) is a whole number m, then n = m². n, therefore is not a prime number. m doesn't have to be prime number because m can be any numbers, prime or not prime, real or imaginary to satisfy the equation m² = n or m = sqrt(n).

 

Interesting, I get it now. I'm going to try it out. Thanks.