1. **State the problem:**
We are given two polynomials:
$$f(x) = 2x (x + 3) (x - 2)^2$$
$$g(x) = -x (x - 2)^2 (x + 3)^3$$
We need to sketch sign charts and determine where each polynomial is positive ($>0$) and negative ($<0$).
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2. **Recall the rules for sign charts:**
- The roots (zeros) of the polynomial are where the function equals zero.
- The sign of the polynomial changes at roots with odd multiplicity.
- The sign does not change at roots with even multiplicity.
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3. **Analyze $f(x)$:**
- Roots: $x=0$ (multiplicity 1), $x=-3$ (multiplicity 1), $x=2$ (multiplicity 2).
- Since $(x-2)^2$ has even multiplicity, sign does not change at $x=2$.
4. **Sign intervals for $f(x)$:**
- Intervals: $(-\infty, -3)$, $(-3, 0)$, $(0, 2)$, $(2, \infty)$.
- Test points:
- For $x=-4$ in $(-\infty, -3)$: $2(-4)(-4+3)(-4-2)^2 = 2(-4)(-1)(36) = 288 > 0$.
- For $x=-1$ in $(-3, 0)$: $2(-1)(-1+3)(-1-2)^2 = 2(-1)(2)(9) = -36 < 0$.
- For $x=1$ in $(0, 2)$: $2(1)(1+3)(1-2)^2 = 2(1)(4)(1) = 8 > 0$.
- For $x=3$ in $(2, \infty)$: $2(3)(3+3)(3-2)^2 = 2(3)(6)(1) = 36 > 0$.
5. **Sign chart for $f(x)$:**
- Positive on $(-\infty, -3)$, $(0, 2)$, and $(2, \infty)$.
- Negative on $(-3, 0)$.
6. **Final solution for $f(x)$:**
- $f(x) > 0$ on $(-\infty, -3) \cup (0, \infty)$.
- $f(x) < 0$ on $(-3, 0)$.
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7. **Analyze $g(x)$:**
- Roots: $x=0$ (multiplicity 1), $x=2$ (multiplicity 2), $x=-3$ (multiplicity 3).
- Sign changes at roots with odd multiplicity: $x=0$ and $x=-3$.
- No sign change at $x=2$ (even multiplicity).
8. **Sign intervals for $g(x)$:**
- Intervals: $(-\infty, -3)$, $(-3, 0)$, $(0, 2)$, $(2, \infty)$.
- Test points:
- For $x=-4$ in $(-\infty, -3)$: $-(-4)(-4-2)^2(-4+3)^3 = -(-4)(36)(-1)^3 = -(-4)(36)(-1) = -144 < 0$.
- For $x=-1$ in $(-3, 0)$: $-(-1)(-1-2)^2(-1+3)^3 = -(-1)(9)(2)^3 = -(-1)(9)(8) = 72 > 0$.
- For $x=1$ in $(0, 2)$: $-(1)(1-2)^2(1+3)^3 = -(1)(1)(4)^3 = -(1)(64) = -64 < 0$.
- For $x=3$ in $(2, \infty)$: $-(3)(3-2)^2(3+3)^3 = -(3)(1)(6)^3 = -(3)(216) = -648 < 0$.
9. **Sign chart for $g(x)$:**
- Positive on $(-3, 0)$.
- Negative on $(-\infty, -3) \cup (0, \infty)$.
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**Summary:**
- For $f(x)$:
- $f(x) > 0$ on $(-\infty, -3) \cup (0, \infty)$
- $f(x) < 0$ on $(-3, 0)$
- For $g(x)$:
- $g(x) > 0$ on $(-3, 0)$
- $g(x) < 0$ on $(-\infty, -3) \cup (0, \infty)$
Polynomial Signs D1E81D
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