1. **State the problem:** We are given a quadratic equation $$x^2 + 12x + k = 0$$ and told that one root is twice the other. We need to find the value of $$k$$.
2. **Recall the relationships between roots and coefficients:** For a quadratic equation $$ax^2 + bx + c = 0$$ with roots $$r_1$$ and $$r_2$$, we have:
- Sum of roots: $$r_1 + r_2 = -\frac{b}{a}$$
- Product of roots: $$r_1 r_2 = \frac{c}{a}$$
3. **Apply to our equation:** Here, $$a=1$$, $$b=12$$, and $$c=k$$. So:
- $$r_1 + r_2 = -12$$
- $$r_1 r_2 = k$$
4. **Use the condition that one root is twice the other:** Let the smaller root be $$r$$, then the other root is $$2r$$.
5. **Write equations using this:**
- Sum: $$r + 2r = 3r = -12 \implies r = -4$$
- Product: $$r \times 2r = 2r^2 = k$$
6. **Calculate $$k$$:**
- $$k = 2 \times (-4)^2 = 2 \times 16 = 32$$
**Final answer:** $$k = 32$$
Quadratic Roots 1201A9
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