Multiple choice general knowledge math & puzzles inegral of Cos x Sin x Sin x Cos x Cos x Reveal answer Fill a bubble to check yourself A Correct answer Explanation The integral of cos(x) dx is sin(x) + C. Since the derivative of sin(x) is cos(x), the antiderivative (integral) of cos(x) must be sin(x). A common mistake is to suggest -sin(x), which is actually the derivative of cos(x).