Differentiate y = (5x + 1)^2 and evaluate dy/dx at x = 0.
Answer and explanation
Correct answer: C. 10
- Step 1: Apply the chain rule: dy/dx = 2 x 5 x (5x + 1)^1.
- Step 2: At x = 0 the inner expression equals 1.
- Step 3: dy/dx = 2 x 5 x 1^1 = 10.
Answer
10.
Why not the others: '2' omits the inner derivative 5 from the chain rule; '1' evaluates y instead of dy/dx; '5' forgets to bring down the exponent 2.
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