Let . What is the value of ?

Answer and explanation

Correct answer: C.

  1. Step 1: First derivative: .
  2. Step 2: Second derivative via quotient rule: .
  3. Step 3: Substitute : .
Answer
.
Why not the others: results from forgetting the negative sign in the quotient numerator; evaluates only ; and is the value of rather than the second derivative.

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