Find f'(3) for f(x) = x^3-2x^2+4x.
Answer and explanation
Correct answer: B. 19
- Step 1: Differentiate term by term with the power rule: f'(x) = 3x^2-4x+4.
- Step 2: Substitute x = 3: f'(3) = 19.
Answer
19.
Why not the others: '21' is f(3), the function value, not the derivative; '25' forgets to multiply the x^2 term's exponent 2 when differentiating; '15' drops the constant slope term c from the derivative.
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