engineering mathematics MCQ #645

engineering mathematics MCQ #645

1. Question 1

   Q1. Find the derivative of sin(x)cos(2x)

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

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

   Explanation: Using product rule, d(sin(x)cos(2x))/dx = sin(x)d(cos(2x))/dx + cos(2x)d(sin(x))/dx = -2sin(x)sin(2x) + cos(x)cos(2x)