Leading coefficient of a polynomial is the coefficient of the highest power of x.
Leading coefficient is inherently non-zero
Monic polynomials: leading coefficient == 1

Rational Root Theorem:
	forall P(x): polynomial of degree n with integer coefficients
	forall p, q: Z such that p/q is a root of P(x)
	p is a factor of a[0]
	q is a factor of a[n]