Why the answer is A, and why the others tempt you.
**The reasoning**
We're using the **power rule of differentiation**: when you differentiate xⁿ, you get n·xⁿ⁻¹.
Let's break down (3x² + 2x - 5) term by term:
- **3x²**: Bring down the power 2, multiply by 3 → 2 × 3x²⁻¹ = **6x**
- **2x**: This is really 2x¹, so bring down the 1 → 1 × 2x⁰ = **2** (since x⁰ = 1)
- **-5**: This is a constant. Constants vanish when differentiated → **0**
Add them up: 6x + 2 + 0 = **6x + 2**
**Why the wrong options tempt you**
- **B (3x + 2)**: You forgot to multiply by the power when differentiating 3x². Easy slip!
- **C (6x - 5)**: You differentiated 2x wrongly (maybe got confused) and kept the constant -5 instead of removing it.
- **D (6x + 2 - 5)**: You kept the constant! Remember: constants always disappear during differentiation because their rate of change is zero.
**Quick takeaway**
When differentiating polynomials, bring down powers and reduce them by 1; constants always vanish because they don't change.
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