engineering mathematics MCQ #870

If f(x) = sin(3x), then f'(x) is

engineering mathematics MCQ #870

  1. Question 1

    Q1. If f(x) = sin(3x), then f'(x) is

    • A) 3cos(3x)
    • B) cos(3x)
    • C) 3sin(3x)
    • D) -3cos(3x)

    Answer: 3cos(3x)

    Explanation: Using chain rule, if y = sin(u) and u = 3x, then dy/dx = cos(u) * du/dx = cos(3x) * 3 = 3cos(3x).