On which interval is the function concave downward?
Answer and explanation
Correct answer: A.
- Step 1: Concavity is determined by the sign of the second derivative .
- Step 2: First derivative: .
- Step 3: Second derivative: .
- Step 4: Set for downward concavity: , which is .
Answer
.
Why not the others: '' is where (concave upward); '' is where is decreasing; '' identifies the interval where .
Practise more Differentiation.
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