Okay, suppose x=a/b, where a,b are integers. Assume that the fraction is reduced, ie. gcd(a,b)=1. Then x^x= (a/b)^(a/b)=(\frac{a^a}{b^a})^\frac{1}{b}
But gcd(a^a,b^a)=1, and therefore (\frac{a^a}{b^a})^\frac{1}{b} is irrational. It follows that if x^x is an integer, then either x is an...