Created by Josh Carlson Easy and Fun Trig Integrals Trig Formulas to Know: Set 2 [ Set 1 ] [ Cos2(x) = ] [ Sin2(x) = ] Set 3 Others You Should Already Know 1 + Tan2(x) = Sec2(x) A: Sin2(x) + Cos2(x) = 1 1 + Cot2(x) = Csc2(x) B: Cos2(x) – Sin2(x) = Cos(2x) Now for the Integration Type 1: ∫Sinn(x)dx or ∫Cosn(x)dx If n is odd If n is even Take out one of the function. Apply appropriate formula from Set 1. Apply Formula A to the now even Keep simplifying and applying the powered part. Use u-substitution to integrate. formulas to all trig with even powers. Integrate each term separately. Type 2: ∫Sinm(x)Cosn(x)dx If one is odd and >0, and the other is anything Take out one of the odd power. Apply Formula A to the now even part of the one you took from. If m and n are even Apply appropriate formulas from Set 1 to both trig parts. Keep simplifying and applying the formulas to all trig with even powers. Use u-substitution to integrate. Integrate each term separately. Note: some terms may look like type 1 where n is odd, but you can do them now!! Created by Josh Carlson Type 3: ∫Sin(Mx)Cos(Nx)dx or ∫Sin(Mx)Sin(Nx)dx or ∫Cos(Mx)Cos(Nx)dx Apply the appropriate formula from Set 2, and then integrate. Type 4: ∫Tann(x)dx or ∫Cotn(x)dx ∫Tann(x)dx → Factor out a Tan2(x) = Sec2(x) – 1, distribute, then integrate each term separately. [Note: if u = Tan(x), then du = Sec2(x)dx] ∫Cotn(x)dx → Factor out a Cot 2(x) = Csc2(x) – 1, distribute, then integrate each term separately. [Note: if u = Cot(x), then du = −Csc2(x)dx] Type 5: ∫Tanm(x)Secn(x)dx or ∫Cotm(x)Cscn(x)dx If n is even and m is any number ∫Tanm(x)Secn(x)dx ∫Cotm(x)Cscn(x)dx Pull out one Sec2(x), and put everything else in terms of Tan(x). Pull out one –Csc2(x), and put everything else in terms of Cot(x). Distribute; integrate with u = Tan(x) 2 Distribute; integrate with u = Cot(x) and du = –Csc2(x)dx. and du = Sec (x)dx. If m is odd and n is any number ∫Tanm(x)Secn(x)dx ∫Cotm(x)Cscn(x)dx Pull out one Sec(x) and a Tan(x), group them together, and put everything else everything else in terms of Cot(x). in terms of Sec(x). Pull out one [−Cot(x)Csc(x)], and put Distribute; integrate with u = Cot(x) and du = −Cot(x)Csc(x)dx. Distribute; integrate with u = Sec(x) and du = Sec(x)Tan(x). Rationalizing Substitutions Anytime you see this in the integrand Substitute this, then integrate √ → , √ → , √ → ,