1. **State the problem:** Find the real zeros of the function $$f(x) = 6(x^2 - 9)(x^2 + 12x + 27)^2$$ and determine their multiplicities.
2. **Recall the formula and rules:** To find real zeros, set $$f(x) = 0$$ and solve for $$x$$. The multiplicity of a zero is the exponent of the factor in the factored form.
3. **Set the function equal to zero:**
$$6(x^2 - 9)(x^2 + 12x + 27)^2 = 0$$
Since 6 is a constant and never zero, we focus on:
$$ (x^2 - 9)(x^2 + 12x + 27)^2 = 0 $$
4. **Solve each factor:**
- For $$x^2 - 9 = 0$$:
$$x^2 = 9$$
$$x = \pm 3$$
- For $$x^2 + 12x + 27 = 0$$, use the quadratic formula:
$$x = \frac{-12 \pm \sqrt{12^2 - 4 \cdot 1 \cdot 27}}{2 \cdot 1} = \frac{-12 \pm \sqrt{144 - 108}}{2} = \frac{-12 \pm \sqrt{36}}{2}$$
$$x = \frac{-12 \pm 6}{2}$$
So,
$$x = \frac{-12 + 6}{2} = \frac{-6}{2} = -3$$
$$x = \frac{-12 - 6}{2} = \frac{-18}{2} = -9$$
5. **List all real zeros:**
$$x = -9, -3, 3$$
6. **Determine multiplicities:**
- The factor $$x^2 - 9$$ can be factored as $$(x - 3)(x + 3)$$, each with multiplicity 1.
- The factor $$(x^2 + 12x + 27)^2$$ has zeros at $$x = -3$$ and $$x = -9$$, each with multiplicity 2 because of the square.
7. **Combine multiplicities for repeated zeros:**
- $$x = 3$$ comes from $$(x - 3)$$ with multiplicity 1.
- $$x = -3$$ appears in both factors: once in $$(x + 3)$$ with multiplicity 1 and once in $$(x^2 + 12x + 27)^2$$ with multiplicity 2, so total multiplicity is $$1 + 2 = 3$$.
- $$x = -9$$ comes from $$(x^2 + 12x + 27)^2$$ with multiplicity 2.
**Final answer:**
- Real zeros: $$-9, -3, 3$$
- Multiplicities: $$-9$$ has multiplicity 2, $$-3$$ has multiplicity 3, $$3$$ has multiplicity 1.
Real Zeros Multiplicity A01406
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