Q37 / 104 · NTA Abhyas (JEE Main) 2020 · Mathematics · Indefinite Integration

∫ sin 8 x− cos 8 x 1−2 sin 2 x cos 2 x dx is equal to (where C is an arbitrary constant)

  • A
    1 2 sin2x+C
  • Correct answer
    B
    − 1 2 sin2x+C
  • C
    − 1 2 sinx+C
  • D
    − sin 2 x+C

Solution

∫sin8x-cos8x1-2sin2xcos2xdx

=∫sin4x-cos4xsin4x + cos4x1-2sin2xcos2xdx

=∫sin2x-cos2xsin4x + cos4x1-2 sin2xcos2xdx

=∫-cos2x dx=-12sin2x + C

Hence, the correct answer is option: 'B'.

More Indefinite Integration Questions