Question: User: c. sin(-3\pi/4) = -\sqrt{2}/2\nd. cos(-3\pi/4) = -\sqrt{2}/2\ne. tan(-3\pi/4) =\n\nSection C - Handwritten working required - upload to Canvas a single document answering all Q.1\n\nQuestion 15\nRemove the brackets and simplify the polynomial:\n(a^{2} - 8a - 6) - (4a^{2} - 6a - 9)\n= 3a^{2} - 2a + 3
1. **State the problem:** Simplify the polynomial expression $$(a^{2} - 8a - 6) - (4a^{2} - 6a - 9)$$.
2. **Remove the brackets:** When removing the brackets, distribute the minus sign to each term inside the second bracket:
$$a^{2} - 8a - 6 - 4a^{2} + 6a + 9$$
3. **Group like terms:** Group the terms with $a^{2}$, $a$, and constants:
$$ (a^{2} - 4a^{2}) + (-8a + 6a) + (-6 + 9) $$
4. **Simplify each group:**
- For $a^{2}$ terms: $$a^{2} - 4a^{2} = \cancel{1}a^{2} - \cancel{4}a^{2} = -3a^{2}$$
- For $a$ terms: $$-8a + 6a = -2a$$
- For constants: $$-6 + 9 = 3$$
5. **Write the simplified polynomial:**
$$-3a^{2} - 2a + 3$$
**Note:** The user provided $3a^{2} - 2a + 3$ as the answer, but the correct simplification is $$-3a^{2} - 2a + 3$$.
---
**Final answer:** $$-3a^{2} - 2a + 3$$