1. **State the problem:** We need to analyze the function $$f(x) = (x - 1)^3 (x + 2)^2$$.
2. **Formula and rules:** This is a polynomial function expressed as a product of powers of linear factors. To understand its behavior, we can find its roots, multiplicities, and analyze the derivative for critical points.
3. **Find roots and multiplicities:** The roots are at $$x=1$$ with multiplicity 3 and $$x=-2$$ with multiplicity 2.
4. **Find the derivative using the product rule:**
$$f'(x) = \frac{d}{dx}[(x - 1)^3] \cdot (x + 2)^2 + (x - 1)^3 \cdot \frac{d}{dx}[(x + 2)^2]$$
Calculate each derivative:
$$\frac{d}{dx}[(x - 1)^3] = 3(x - 1)^2$$
$$\frac{d}{dx}[(x + 2)^2] = 2(x + 2)$$
So,
$$f'(x) = 3(x - 1)^2 (x + 2)^2 + (x - 1)^3 2(x + 2)$$
5. **Factor the derivative:**
$$f'(x) = (x - 1)^2 (x + 2) [3(x + 2) + 2(x - 1)]$$
Simplify inside the bracket:
$$3(x + 2) + 2(x - 1) = 3x + 6 + 2x - 2 = 5x + 4$$
Thus,
$$f'(x) = (x - 1)^2 (x + 2) (5x + 4)$$
6. **Find critical points by setting $$f'(x) = 0$$:**
$$ (x - 1)^2 = 0 \Rightarrow x = 1$$
$$ (x + 2) = 0 \Rightarrow x = -2$$
$$ (5x + 4) = 0 \Rightarrow x = -\frac{4}{5}$$
7. **Summary:**
- Roots of $$f(x)$$ at $$x=1$$ (multiplicity 3) and $$x=-2$$ (multiplicity 2).
- Critical points at $$x=1$$, $$x=-2$$, and $$x=-\frac{4}{5}$$.
This analysis helps understand the shape and turning points of the function.
Polynomial Analysis E42E10
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