What is the derivative of x · sin(x) using the product rule? A sin(x) + x·cos(x) B x·cos(x) C sin(x)·cos(x) D cos(x) − x·sin(x) ✓ Correct Answer: Option A Product rule: d/dx[x·sin(x)] = 1·sin(x) + x·cos(x) = sin(x) + x·cos(x). Practice AP Exam Prep Quizzes → Browse All Questions Study Flashcards