Chapter 5 Polynomials and Polynomial Functions - 5.7 Apply the Fundamental Theorem of Algebra - 5.7 Exercises - Skill Practice - Page 384: 51

Positive real zeros = 2 or 0 Negative real zeros= 1 Minimum number of complex roots = Zero

Here, we have $f(x)=x^3+x^2-x-1$ By Descartes' Rule, we have either $2$ or $0$ positive real roots. Now, $f(-x)=-x^3+x^2+x-1$ By Descartes' Rule, we have $1$ negative real root. Positive real zeros = 2 or 0 Negative real zeros= 1 Minimum number of complex roots = Zero