1. **State the problem:** We have the function $$f(x) = x^4 - ax^3 + ax^2 - 2x + 1$$ with $$a = 2$$ and the factorization $$f(x) = (x - 1) \cdot g(x)$$. We want to find the values of $$x \in \mathbb{R}$$ such that $$f(x) \geq 0$$.
2. **Substitute the value of $$a$$:**
$$f(x) = x^4 - 2x^3 + 2x^2 - 2x + 1$$
3. **Use the factorization:** Since $$f(x) = (x - 1) \cdot g(x)$$, divide $$f(x)$$ by $$x - 1$$ to find $$g(x)$$.
4. **Polynomial division:**
Divide $$x^4 - 2x^3 + 2x^2 - 2x + 1$$ by $$x - 1$$:
- Leading term: $$x^4 / x = x^3$$
- Multiply: $$x^3(x - 1) = x^4 - x^3$$
- Subtract: $$(-2x^3) - (-x^3) = -x^3$$
- Bring down $$+ 2x^2$$
- Next term: $$-x^3 / x = -x^2$$
- Multiply: $$-x^2(x - 1) = -x^3 + x^2$$
- Subtract: $$2x^2 - x^2 = x^2$$
- Bring down $$- 2x$$
- Next term: $$x^2 / x = x$$
- Multiply: $$x(x - 1) = x^2 - x$$
- Subtract: $$-2x - (-x) = -x$$
- Bring down $$+ 1$$
- Next term: $$-x / x = -1$$
- Multiply: $$-1(x - 1) = -x + 1$$
- Subtract: $$1 - 1 = 0$$
So, $$g(x) = x^3 - x^2 + x - 1$$.
5. **Rewrite $$f(x)$$:**
$$f(x) = (x - 1)(x^3 - x^2 + x - 1)$$
6. **Factor $$g(x)$$ further:**
Try to factor $$g(x) = x^3 - x^2 + x - 1$$ by grouping:
$$x^3 - x^2 + x - 1 = (x^3 - x^2) + (x - 1) = x^2(x - 1) + 1(x - 1) = (x - 1)(x^2 + 1)$$
7. **Complete factorization:**
$$f(x) = (x - 1)^2 (x^2 + 1)$$
8. **Analyze the inequality $$f(x) \geq 0$$:**
- Since $$x^2 + 1 > 0$$ for all real $$x$$,
- The sign of $$f(x)$$ depends on $$(x - 1)^2$$ which is always $$\geq 0$$.
9. **Conclusion:**
$$f(x) \geq 0$$ for all real $$x$$, and $$f(x) = 0$$ only at $$x = 1$$.
**Final answer:**
$$\boxed{\text{For all } x \in \mathbb{R}, f(x) \geq 0 \text{ and } f(x) = 0 \text{ only at } x = 1}$$
Polynomial Inequality 827A25
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