engineering mathematics MCQ #683

If y = sin(x)cos(2x), then dy/dx = ?

engineering mathematics MCQ #683

  1. Question 1

    Q1. If y = sin(x)cos(2x), then dy/dx = ?

    • A) cos(x)cos(2x) - 2sin(x)sin(2x)
    • B) cos(x)cos(2x) + 2sin(x)sin(2x)
    • C) cos(x)sin(2x) - 2sin(x)cos(2x)
    • D) cos(x)sin(2x) + 2sin(x)cos(2x)

    Answer: cos(x)cos(2x) - 2sin(x)sin(2x)

    Explanation: Using product rule and chain rule, dy/dx = cos(x)cos(2x) + sin(x)(-2sin(2x)) = cos(x)cos(2x) - 2sin(x)sin(2x).