List of integrals of trigonometric functions

Trigonometry
History Usage Functions Generalized Inverse functions Further reading
Reference
Identities Exact constants Trigonometric tables
Laws and theorems
Law of sines Law of cosines Law of tangents Law of cotangents Pythagorean theorem
Calculus
Trigonometric substitution Integrals of functions Derivatives of functions Integrals of inverse functions

The following is a list of integrals (antiderivative functions) of trigonometric functions. For antiderivatives involving both exponential and trigonometric functions, see List of integrals of exponential functions. For a complete list of antiderivative functions, see lists of integrals. See also trigonometric integral.

Generally, if the function $\sin(x)$ is any trigonometric function, and $\cos(x)$ is its derivative,

$\int a\cos nx\;\mathrm{d}x = \frac{a}{n}\sin nx+C$

In all formulas the constant a is assumed to be nonzero, and C denotes the constant of integration.

Integrals involving only sine

$\int\sin ax\;\mathrm{d}x = -\frac{1}{a}\cos ax+C\,\!$

$\int\sin^2 {ax}\;\mathrm{d}x = \frac{x}{2} - \frac{1}{4a} \sin 2ax +C= \frac{x}{2} - \frac{1}{2a} \sin ax\cos ax +C\!$

$\int\sin^3 {ax}\;\mathrm{d}x = \frac{\cos 3ax}{12a} - \frac{3 \cos ax}{4a} +C\!$

$\int x\sin^2 {ax}\;\mathrm{d}x = \frac{x^2}{4} - \frac{x}{4a} \sin 2ax - \frac{1}{8a^2} \cos 2ax +C\!$

$\int x^2\sin^2 {ax}\;\mathrm{d}x = \frac{x^3}{6} - \left( \frac {x^2}{4a} - \frac{1}{8a^3} \right) \sin 2ax - \frac{x}{4a^2} \cos 2ax +C\!$

$\int\sin b_1x\sin b_2x\;\mathrm{d}x = \frac{\sin((b_2-b_1)x)}{2(b_2-b_1)}-\frac{\sin((b_1+b_2)x)}{2(b_1+b_2)}+C \qquad\mbox{(for }|b_1|\neq|b_2|\mbox{)}\,\!$

$\int\sin^n {ax}\;\mathrm{d}x = -\frac{\sin^{n-1} ax\cos ax}{na} + \frac{n-1}{n}\int\sin^{n-2} ax\;\mathrm{d}x \qquad\mbox{(for }n>2\mbox{)}\,\!$

$\int\frac{\mathrm{d}x}{\sin ax} = \frac{1}{a}\ln \left|\tan\frac{ax}{2}\right|+C$

$\int\frac{\mathrm{d}x}{\sin^n ax} = \frac{\cos ax}{a(1-n) \sin^{n-1} ax}+\frac{n-2}{n-1}\int\frac{\mathrm{d}x}{\sin^{n-2}ax} \qquad\mbox{(for }n>1\mbox{)}\,\!$

$\int x\sin ax\;\mathrm{d}x = \frac{\sin ax}{a^2}-\frac{x\cos ax}{a}+C\,\!$

$\int x^n\sin ax\;\mathrm{d}x = -\frac{x^n}{a}\cos ax+\frac{n}{a}\int x^{n-1}\cos ax\;\mathrm{d}x = \sum_{k=0}^{2k\leq n} (-1)^{k+1} \frac{x^{n-2k}}{a^{1+2k}}\frac{n!}{(n-2k)!} \cos ax +\sum_{k=0}^{2k+1\leq n}(-1)^k \frac{x^{n-1-2k}}{a^{2+2k}}\frac{n!}{(n-2k-1)!} \sin ax \qquad\mbox{(for }n>0\mbox{)}\,\!$

$\int_{\frac{-a}{2}}^{\frac{a}{2}} x^2\sin^2 {\frac{n\pi x}{a}}\;\mathrm{d}x = \frac{a^3(n^2\pi^2-6)}{24n^2\pi^2} \qquad\mbox{(for }n=2,4,6...\mbox{)}\,\!$

$\int\frac{\sin ax}{x} \mathrm{d}x = \sum_{n=0}^\infty (-1)^n\frac{(ax)^{2n+1}}{(2n+1)\cdot (2n+1)!} +C\,\!$

$\int\frac{\sin ax}{x^n} \mathrm{d}x = -\frac{\sin ax}{(n-1)x^{n-1}} + \frac{a}{n-1}\int\frac{\cos ax}{x^{n-1}} \mathrm{d}x\,\!$

$\int\frac{\mathrm{d}x}{1\pm\sin ax} = \frac{1}{a}\tan\left(\frac{ax}{2}\mp\frac{\pi}{4}\right)+C$

$\int\frac{x\;\mathrm{d}x}{1+\sin ax} = \frac{x}{a}\tan\left(\frac{ax}{2} - \frac{\pi}{4}\right)+\frac{2}{a^2}\ln\left|\cos\left(\frac{ax}{2}-\frac{\pi}{4}\right)\right|+C$

$\int\frac{x\;\mathrm{d}x}{1-\sin ax} = \frac{x}{a}\cot\left(\frac{\pi}{4} - \frac{ax}{2}\right)+\frac{2}{a^2}\ln\left|\sin\left(\frac{\pi}{4}-\frac{ax}{2}\right)\right|+C$

$\int\frac{\sin ax\;\mathrm{d}x}{1\pm\sin ax} = \pm x+\frac{1}{a}\tan\left(\frac{\pi}{4}\mp\frac{ax}{2}\right)+C$

Integrands involving only cosine

$\int\cos ax\;\mathrm{d}x = \frac{1}{a}\sin ax+C\,\!$

$\int\cos^2 {ax}\;\mathrm{d}x = \frac{x}{2} + \frac{1}{4a} \sin 2ax +C = \frac{x}{2} + \frac{1}{2a} \sin ax\cos ax +C\!$

$\int\cos^n ax\;\mathrm{d}x = \frac{\cos^{n-1} ax\sin ax}{na} + \frac{n-1}{n}\int\cos^{n-2} ax\;\mathrm{d}x \qquad\mbox{(for }n>0\mbox{)}\,\!$

$\int x\cos ax\;\mathrm{d}x = \frac{\cos ax}{a^2} + \frac{x\sin ax}{a}+C\,\!$

$\int x^2\cos^2 {ax}\;\mathrm{d}x = \frac{x^3}{6} + \left( \frac {x^2}{4a} - \frac{1}{8a^3} \right) \sin 2ax + \frac{x}{4a^2} \cos 2ax +C\!$

$\int x^n\cos ax\;\mathrm{d}x = \frac{x^n\sin ax}{a} - \frac{n}{a}\int x^{n-1}\sin ax\;\mathrm{d}x\,= \sum_{k=0}^{2k+1\leq n} (-1)^{k} \frac{x^{n-2k-1}}{a^{2+2k}}\frac{n!}{(n-2k-1)!} \cos ax +\sum_{k=0}^{2k\leq n}(-1)^{k} \frac{x^{n-2k}}{a^{1+2k}}\frac{n!}{(n-2k)!} \sin ax \!$

$\int\frac{\cos ax}{x} \mathrm{d}x = \ln|ax|+\sum_{k=1}^\infty (-1)^k\frac{(ax)^{2k}}{2k\cdot(2k)!}+C\,\!$

$\int\frac{\cos ax}{x^n} \mathrm{d}x = -\frac{\cos ax}{(n-1)x^{n-1}}-\frac{a}{n-1}\int\frac{\sin ax}{x^{n-1}} \mathrm{d}x \qquad\mbox{(for }n\neq 1\mbox{)}\,\!$

$\int\frac{\mathrm{d}x}{\cos ax} = \frac{1}{a}\ln\left|\tan\left(\frac{ax}{2}+\frac{\pi}{4}\right)\right|+C$

$\int\frac{\mathrm{d}x}{\cos^n ax} = \frac{\sin ax}{a(n-1) \cos^{n-1} ax} + \frac{n-2}{n-1}\int\frac{\mathrm{d}x}{\cos^{n-2} ax} \qquad\mbox{(for }n>1\mbox{)}\,\!$

$\int\frac{\mathrm{d}x}{1+\cos ax} = \frac{1}{a}\tan\frac{ax}{2}+C\,\!$

$\int\frac{\mathrm{d}x}{1-\cos ax} = -\frac{1}{a}\cot\frac{ax}{2}+C$

$\int\frac{x\;\mathrm{d}x}{1+\cos ax} = \frac{x}{a}\tan\frac{ax}{2} + \frac{2}{a^2}\ln\left|\cos\frac{ax}{2}\right|+C$

$\int\frac{x\;\mathrm{d}x}{1-\cos ax} = -\frac{x}{a}\cot\frac{ax}{2}+\frac{2}{a^2}\ln\left|\sin\frac{ax}{2}\right|+C$

$\int\frac{\cos ax\;\mathrm{d}x}{1+\cos ax} = x - \frac{1}{a}\tan\frac{ax}{2}+C\,\!$

$\int\frac{\cos ax\;\mathrm{d}x}{1-\cos ax} = -x-\frac{1}{a}\cot\frac{ax}{2}+C\,\!$

$\int\cos a_1x\cos a_2x\;\mathrm{d}x = \frac{\sin(a_2-a_1)x}{2(a_2-a_1)}+\frac{\sin(a_2+a_1)x}{2(a_2+a_1)}+C \qquad\mbox{(for }|a_1|\neq|a_2|\mbox{)}\,\!$

Integrands involving only tangent

$\int\tan ax\;\mathrm{d}x = -\frac{1}{a}\ln|\cos ax|+C = \frac{1}{a}\ln|\sec ax|+C\,\!$

$\int\tan^n ax\;\mathrm{d}x = \frac{1}{a(n-1)}\tan^{n-1} ax-\int\tan^{n-2} ax\;\mathrm{d}x \qquad\mbox{(for }n\neq 1\mbox{)}\,\!$

$\int\frac{\mathrm{d}x}{q \tan ax + p} = \frac{1}{p^2 + q^2}(px + \frac{q}{a}\ln|q\sin ax + p\cos ax|)+C \qquad\mbox{(for }p^2 + q^2\neq 0\mbox{)}\,\!$

$\int\frac{\mathrm{d}x}{\tan ax + 1} = \frac{x}{2} + \frac{1}{2a}\ln|\sin ax + \cos ax|+C\,\!$

$\int\frac{\mathrm{d}x}{\tan ax - 1} = -\frac{x}{2} + \frac{1}{2a}\ln|\sin ax - \cos ax|+C\,\!$

$\int\frac{\tan ax\;\mathrm{d}x}{\tan ax + 1} = \frac{x}{2} - \frac{1}{2a}\ln|\sin ax + \cos ax|+C\,\!$

$\int\frac{\tan ax\;\mathrm{d}x}{\tan ax - 1} = \frac{x}{2} + \frac{1}{2a}\ln|\sin ax - \cos ax|+C\,\!$

Integrands involving only secant

See Integral of the secant function.

$\int \sec{ax} \, \mathrm{d}x = \frac{1}{a}\ln{\left| \sec{ax} + \tan{ax}\right|}+C$

$\int \sec^2{x} \, \mathrm{d}x = \tan{x}+C$

$\int \sec^n{ax} \, \mathrm{d}x = \frac{\sec^{n-2}{ax} \tan {ax}}{a(n-1)} \,+\, \frac{n-2}{n-1}\int \sec^{n-2}{ax} \, \mathrm{d}x \qquad \mbox{ (for }n \ne 1\mbox{)}\,\!$

$\int \sec^n{x} \, \mathrm{d}x = \frac{\sec^{n-2}{x}\tan{x}}{n-1} \,+\, \frac{n-2}{n-1}\int \sec^{n-2}{x}\,\mathrm{d}x$

$\int \frac{\mathrm{d}x}{\sec{x} + 1} = x - \tan{\frac{x}{2}}+C$

$\int \frac{\mathrm{d}x}{\sec{x} - 1} = - x - \cot{\frac{x}{2}}+C$

$\int \sec{ax} \, \mathrm{d}x = \frac{1}{a}\ln{\left| \sec{ax} + \tan{ax}\right|}+C$

Integrands involving only cosecant

$\int \csc{ax} \, \mathrm{d}x = \frac{1}{a}\ln{\left| \csc{ax}-\cot{ax}\right|}+C$

$\int \csc^2{x} \, \mathrm{d}x = -\cot{x}+C$

$\int \csc^n{ax} \, \mathrm{d}x = -\frac{\csc^{n-1}{ax} \cos{ax}}{a(n-1)} \,+\, \frac{n-2}{n-1}\int \csc^{n-2}{ax} \, \mathrm{d}x \qquad \mbox{ (for }n \ne 1\mbox{)}\,\!$

$\int \frac{\mathrm{d}x}{\csc{x} + 1} = x - \frac{2\sin{\frac{x}{2}}}{\cos{\frac{x}{2}}+\sin{\frac{x}{2}}}+C$

$\int \frac{\mathrm{d}x}{\csc{x} - 1} = \frac{2\sin{\frac{x}{2}}}{\cos{\frac{x}{2}}-\sin{\frac{x}{2}}}-x+C$

Integrands involving only cotangent

$\int\cot ax\;\mathrm{d}x = \frac{1}{a}\ln|\sin ax|+C\,\!$

$\int\cot^n ax\;\mathrm{d}x = -\frac{1}{a(n-1)}\cot^{n-1} ax - \int\cot^{n-2} ax\;\mathrm{d}x \qquad\mbox{(for }n\neq 1\mbox{)}\,\!$

$\int\frac{\mathrm{d}x}{1 + \cot ax} = \int\frac{\tan ax\;\mathrm{d}x}{\tan ax+1}\,\!$

$\int\frac{\mathrm{d}x}{1 - \cot ax} = \int\frac{\tan ax\;\mathrm{d}x}{\tan ax-1}\,\!$

Integrands involving both sine and cosine

$\int\frac{\mathrm{d}x}{\cos ax\pm\sin ax} = \frac{1}{a\sqrt{2}}\ln\left|\tan\left(\frac{ax}{2}\pm\frac{\pi}{8}\right)\right|+C$

$\int\frac{\mathrm{d}x}{(\cos ax\pm\sin ax)^2} = \frac{1}{2a}\tan\left(ax\mp\frac{\pi}{4}\right)+C$

$\int\frac{\mathrm{d}x}{(\cos x + \sin x)^n} = \frac{1}{n-1}\left(\frac{\sin x - \cos x}{(\cos x + \sin x)^{n - 1}} - 2(n - 2)\int\frac{\mathrm{d}x}{(\cos x + \sin x)^{n-2}} \right)$

$\int\frac{\cos ax\;\mathrm{d}x}{\cos ax + \sin ax} = \frac{x}{2} + \frac{1}{2a}\ln\left|\sin ax + \cos ax\right|+C$

$\int\frac{\cos ax\;\mathrm{d}x}{\cos ax - \sin ax} = \frac{x}{2} - \frac{1}{2a}\ln\left|\sin ax - \cos ax\right|+C$

$\int\frac{\sin ax\;\mathrm{d}x}{\cos ax + \sin ax} = \frac{x}{2} - \frac{1}{2a}\ln\left|\sin ax + \cos ax\right|+C$

$\int\frac{\sin ax\;\mathrm{d}x}{\cos ax - \sin ax} = -\frac{x}{2} - \frac{1}{2a}\ln\left|\sin ax - \cos ax\right|+C$

$\int\frac{\cos ax\;\mathrm{d}x}{\sin ax(1+\cos ax)} = -\frac{1}{4a}\tan^2\frac{ax}{2}+\frac{1}{2a}\ln\left|\tan\frac{ax}{2}\right|+C$

$\int\frac{\cos ax\;\mathrm{d}x}{\sin ax(1-\cos ax)} = -\frac{1}{4a}\cot^2\frac{ax}{2}-\frac{1}{2a}\ln\left|\tan\frac{ax}{2}\right|+C$

$\int\frac{\sin ax\;\mathrm{d}x}{\cos ax(1+\sin ax)} = \frac{1}{4a}\cot^2\left(\frac{ax}{2}+\frac{\pi}{4}\right)+\frac{1}{2a}\ln\left|\tan\left(\frac{ax}{2}+\frac{\pi}{4}\right)\right|+C$

$\int\frac{\sin ax\;\mathrm{d}x}{\cos ax(1-\sin ax)} = \frac{1}{4a}\tan^2\left(\frac{ax}{2}+\frac{\pi}{4}\right)-\frac{1}{2a}\ln\left|\tan\left(\frac{ax}{2}+\frac{\pi}{4}\right)\right|+C$

$\int\sin ax\cos ax\;\mathrm{d}x = -\frac{1}{2a}\cos^2 ax +C\,\!$

$\int\sin a_1x\cos a_2x\;\mathrm{d}x = -\frac{\cos((a_1-a_2)x)}{2(a_1-a_2)} -\frac{\cos((a_1+a_2)x)}{2(a_1+a_2)} +C\qquad\mbox{(for }|a_1|\neq|a_2|\mbox{)}\,\!$

$\int\sin^n ax\cos ax\;\mathrm{d}x = \frac{1}{a(n+1)}\sin^{n+1} ax +C\qquad\mbox{(for }n\neq -1\mbox{)}\,\!$

$\int\sin ax\cos^n ax\;\mathrm{d}x = -\frac{1}{a(n+1)}\cos^{n+1} ax +C\qquad\mbox{(for }n\neq -1\mbox{)}\,\!$

$\int\sin^n ax\cos^m ax\;\mathrm{d}x = -\frac{\sin^{n-1} ax\cos^{m+1} ax}{a(n+m)}+\frac{n-1}{n+m}\int\sin^{n-2} ax\cos^m ax\;\mathrm{d}x \qquad\mbox{(for }m,n>0\mbox{)}\,\!$

also: $\int\sin^n ax\cos^m ax\;\mathrm{d}x = \frac{\sin^{n+1} ax\cos^{m-1} ax}{a(n+m)} + \frac{m-1}{n+m}\int\sin^n ax\cos^{m-2} ax\;\mathrm{d}x \qquad\mbox{(for }m,n>0\mbox{)}\,\!$

$\int\frac{\mathrm{d}x}{\sin ax\cos ax} = \frac{1}{a}\ln\left|\tan ax\right|+C$

$\int\frac{\mathrm{d}x}{\sin ax\cos^n ax} = \frac{1}{a(n-1)\cos^{n-1} ax}+\int\frac{\mathrm{d}x}{\sin ax\cos^{n-2} ax} \qquad\mbox{(for }n\neq 1\mbox{)}\,\!$

$\int\frac{\mathrm{d}x}{\sin^n ax\cos ax} = -\frac{1}{a(n-1)\sin^{n-1} ax}+\int\frac{\mathrm{d}x}{\sin^{n-2} ax\cos ax} \qquad\mbox{(for }n\neq 1\mbox{)}\,\!$

$\int\frac{\sin ax\;\mathrm{d}x}{\cos^n ax} = \frac{1}{a(n-1)\cos^{n-1} ax} +C\qquad\mbox{(for }n\neq 1\mbox{)}\,\!$

$\int\frac{\sin^2 ax\;\mathrm{d}x}{\cos ax} = -\frac{1}{a}\sin ax+\frac{1}{a}\ln\left|\tan\left(\frac{\pi}{4}+\frac{ax}{2}\right)\right|+C$

$\int\frac{\sin^2 ax\;\mathrm{d}x}{\cos^n ax} = \frac{\sin ax}{a(n-1)\cos^{n-1}ax}-\frac{1}{n-1}\int\frac{\mathrm{d}x}{\cos^{n-2}ax} \qquad\mbox{(for }n\neq 1\mbox{)}\,\!$

$\int\frac{\sin^n ax\;\mathrm{d}x}{\cos ax} = -\frac{\sin^{n-1} ax}{a(n-1)} + \int\frac{\sin^{n-2} ax\;\mathrm{d}x}{\cos ax} \qquad\mbox{(for }n\neq 1\mbox{)}\,\!$

$\int\frac{\sin^n ax\;\mathrm{d}x}{\cos^m ax} = \frac{\sin^{n+1} ax}{a(m-1)\cos^{m-1} ax}-\frac{n-m+2}{m-1}\int\frac{\sin^n ax\;\mathrm{d}x}{\cos^{m-2} ax} \qquad\mbox{(for }m\neq 1\mbox{)}\,\!$

also: $\int\frac{\sin^n ax\;\mathrm{d}x}{\cos^m ax} = -\frac{\sin^{n-1} ax}{a(n-m)\cos^{m-1} ax}+\frac{n-1}{n-m}\int\frac{\sin^{n-2} ax\;\mathrm{d}x}{\cos^m ax} \qquad\mbox{(for }m\neq n\mbox{)}\,\!$

also: $\int\frac{\sin^n ax\;\mathrm{d}x}{\cos^m ax} = \frac{\sin^{n-1} ax}{a(m-1)\cos^{m-1} ax}-\frac{n-1}{m-1}\int\frac{\sin^{n-2} ax\;\mathrm{d}x}{\cos^{m-2} ax} \qquad\mbox{(for }m\neq 1\mbox{)}\,\!$

$\int\frac{\cos ax\;\mathrm{d}x}{\sin^n ax} = -\frac{1}{a(n-1)\sin^{n-1} ax} +C\qquad\mbox{(for }n\neq 1\mbox{)}\,\!$

$\int\frac{\cos^2 ax\;\mathrm{d}x}{\sin ax} = \frac{1}{a}\left(\cos ax+\ln\left|\tan\frac{ax}{2}\right|\right) +C$

$\int\frac{\cos^2 ax\;\mathrm{d}x}{\sin^n ax} = -\frac{1}{n-1}\left(\frac{\cos ax}{a\sin^{n-1} ax)}+\int\frac{\mathrm{d}x}{\sin^{n-2} ax}\right) \qquad\mbox{(for }n\neq 1\mbox{)}$

$\int\frac{\cos^n ax\;\mathrm{d}x}{\sin^m ax} = -\frac{\cos^{n+1} ax}{a(m-1)\sin^{m-1} ax} - \frac{n-m-2}{m-1}\int\frac{\cos^n ax\;\mathrm{d}x}{\sin^{m-2} ax} \qquad\mbox{(for }m\neq 1\mbox{)}\,\!$

also: $\int\frac{\cos^n ax\;\mathrm{d}x}{\sin^m ax} = \frac{\cos^{n-1} ax}{a(n-m)\sin^{m-1} ax} + \frac{n-1}{n-m}\int\frac{\cos^{n-2} ax\;\mathrm{d}x}{\sin^m ax} \qquad\mbox{(for }m\neq n\mbox{)}\,\!$

also: $\int\frac{\cos^n ax\;\mathrm{d}x}{\sin^m ax} = -\frac{\cos^{n-1} ax}{a(m-1)\sin^{m-1} ax} - \frac{n-1}{m-1}\int\frac{\cos^{n-2} ax\;\mathrm{d}x}{\sin^{m-2} ax} \qquad\mbox{(for }m\neq 1\mbox{)}\,\!$

Integrands involving both sine and tangent

$\int \sin ax \tan ax\;\mathrm{d}x = \frac{1}{a}(\ln|\sec ax + \tan ax| - \sin ax)+C\,\!$

$\int\frac{\tan^n ax\;\mathrm{d}x}{\sin^2 ax} = \frac{1}{a(n-1)}\tan^{n-1} (ax) +C\qquad\mbox{(for }n\neq 1\mbox{)}\,\!$

Integrands involving both cosine and tangent

$\int\frac{\tan^n ax\;\mathrm{d}x}{\cos^2 ax} = \frac{1}{a(n+1)}\tan^{n+1} ax +C\qquad\mbox{(for }n\neq -1\mbox{)}\,\!$

Integrals containing both sine and cotangent

$\int\frac{\cot^n ax\;\mathrm{d}x}{\sin^2 ax} = -\frac{1}{a(n+1)}\cot^{n+1} ax +C\qquad\mbox{(for }n\neq -1\mbox{)}\,\!$

Integrands involving both cosine and cotangent

$\int\frac{\cot^n ax\;\mathrm{d}x}{\cos^2 ax} = \frac{1}{a(1-n)}\tan^{1-n} ax +C\qquad\mbox{(for }n\neq 1\mbox{)}\,\!$

Integrals with symmetric limits

$\int_{{-c}}^{{c}}\sin {x}\;\mathrm{d}x = 0 \!$

$\int_{{-c}}^{{c}}\cos {x}\;\mathrm{d}x = 2\int_{{0}}^{{c}}\cos {x}\;\mathrm{d}x = 2\int_{{-c}}^{{0}}\cos {x}\;\mathrm{d}x = 2\sin {c} \!$

$\int_{{-c}}^{{c}}\tan {x}\;\mathrm{d}x = 0 \!$

$\int_{-\frac{a}{2}}^{\frac{a}{2}} x^2\cos^2 {\frac{n\pi x}{a}}\;\mathrm{d}x = \frac{a^3(n^2\pi^2-6)}{24n^2\pi^2} \qquad\mbox{(for }n=1,3,5...\mbox{)}\,\!$