Multiple choice general knowledge math & puzzles Integral of Sin x Cos x Cos x Tan x Sin x Reveal answer Fill a bubble to check yourself B Correct answer Explanation The integral of sin(x) dx is -cos(x) + C. This is because the derivative of cos(x) is -sin(x), so the derivative of -cos(x) is sin(x). Positive cos(x) is the derivative of sin(x), not its integral.