(3 marks] 6. Mary finds that COS X dax - - In | sin(ac) | + C. sin x John finds that I COS X dx = In 10(sin x + cot x cos x) | + C. sin x After being puzzled for a few minutes they realize they are both correct. With- out differentiating the antiderivatives explain why both answers are correct. [Hint: to receive full marks a computation is required.]