Create problem-3.py
Create problem-3.py

Finds largest prime factor of the number 600851475143.
Includes functions:
prime_check(n): checks if a natural number ( no zero ) is prime.
generate_primes(n): returns a list of primes less than n. Accepts negative ints, but returns only positive in list.
trial_factor(n): takes a natural numbern, generates primes less than sqrt(n) + 1, and returns largest of primes which is a factor of n.
David0leo/project-euler-python