Factor Cubic 31351F
1. **State the problem:** Factor the cubic polynomial $x^3 + x^2 - x - 1$.
2. **Recall the factoring method:** For cubic polynomials, try factoring by grouping or use the Rational Root Theorem to find roots.
3. **Apply factoring by grouping:** Group terms as $(x^3 + x^2) + (-x - 1)$.
4. **Factor each group:**
$$x^2(x + 1) - 1(x + 1)$$
5. **Factor out the common binomial:**
$$(x^2 - 1)(x + 1)$$
6. **Recognize difference of squares:**
$$x^2 - 1 = (x - 1)(x + 1)$$
7. **Write the full factorization:**
$$(x - 1)(x + 1)(x + 1) = (x - 1)(x + 1)^2$$
**Final answer:**
$$x^3 + x^2 - x - 1 = (x - 1)(x + 1)^2$$