Question

What are the possible rational zeros of f(x) = x4 + 2x3 – 3x2 – 4x + 18 ?

Answer 1

Forget rational, It even doesn't have any real roots!
http://www.wolframalpha.com/input/?i=x%5E4++%2B2x%5E3+%E2%80%93+3x%5E2+%E2%80%93+4x+%2B++18

Answer 2

so it hasn't any real roots then possible rational roots =0
Apply "Descartes rule" or "Storm's theorem" to get this.
If u don't know these. trey to search on Google about these:)

Answer 3

try*