Let f(x) = 3x^3 - 3x^2 + 6x + 2. What is f'(3)?
Answer and explanation
Correct answer: D. 69
- Step 1: Differentiate term by term: f'(x) = 9x^2 - 6x + 6.
- Step 2: Substitute x = 3: f'(3) = 69.
Answer
69.
Why not the others: 74 is the value of f itself; 48 is the second derivative; 66 adds the coefficient of x a second time.
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