Apply Descartes' Rule to P(−x)=x4+3x3+2x2−x−1P(-x) = x^4 + 3x^3 + 2x^2 - x - 1P(−x)=x4+3x3+2x2−x−1 to find possible negative real roots of P(x)P(x)P(x).
222 or 000
333 or 111
444 or 222
111