f(x) = 2x³ - 5x² + 3x - 1
If there are any rational zeros, then when it is reduced to lowest terms,
its numerator must be a factor of the absolute value of the last term, and
the denominator must be a factor of the absolute value of the leading coefficient.
Absolute value of last term = |-1| = 1 which has 1 as its only factor.
Absolute value of leading coefficient = |2| = 1 which has factors 1 and 2.
Possible numerator for rational zeros in lowest terms: ±1
Possible denominators for rational zeros in lowest terms: ±1, ±2
Possible rational zeros: ±1, 
As it turns out, none of those are zeros.
Edwin
