FORMULAS TO KNOW Some trig identities: sin2 x + cos2 x = 1 tan2 x + 1 = sec2 x sin 2x = 2 sin x cos x cos 2x = 2 cos2 x − 1 tan x = sin x cos x sec x = 1 cos x cot x = cos x sin x csc x = 1 sin x Some integration formulas: R xn dx = xn+1 n+1 +C R 1 x R ex dx = ex + C R sin x dx = −cos x + C R cos x dx = sin x + C R sec2 x dx = tan x + C R tan x sec x dx = sec x + C R tan x dx = ln|sec x| + C R dx x2 +a2 R √ dx a2 −x2 dx = ln|x| + C = 1 a tan−1 ( xa ) + C = sin−1 ( xa ) + C 1