This is the program....

An integer is said to be prime if it is divisible by only 1 and itself. For example 2,3,5 and 7 are prime, but 4,6,8 and 9 are not.

---A) Write a function that determines weather a number is prime.

---B) Use this function in a program that determines and prints all the prime numbers between 1 and 10,000. HOw many of these 10,000 numbers do you really have to test before being sure that you have found all the primes.

---C) Initially, you might think that n/2 is the upper limit for which you must test to see whether a number is prime, but you need only go as high as the square root of n. WHY? Rewrite a program and run it both ways. Estimate the performance improvement.

........PLEASE HELP!!!!!!!! I was able to do every other program for the exception of this one........and this is the most important of them all..............HELP!!!!!!!!!!!!!!!!!!!!!!