Math Formulas
Trigonometric Definite Integrals Formulas
$\int^{\pi/2}_0 \sin^2x\,dx = \int^{\pi/2}_0 \cos^2x\,dx = \dfrac{\pi}{4} \\$
$\int^\infty_0 \dfrac{\sin(px)}{x} \,dx = \left\{
\begin{array}{l l l}
\pi/2 & p > 0 \\
~0 & p = 0 \\
-\pi/2 & p < 0 \\
\end{array} \right.\\$
$\int^\infty_0 \dfrac{\sin^2px}{x^2}~dx = \dfrac{\pi\,p}{2}\\$
$\int^\infty_0 \dfrac{1 - \cos(px)}{x^2}~dx = \dfrac{\pi\,p}{2} \\$
$\int^\infty_0 \dfrac{\cos(px) - \cos(qx)}{x}~dx = ln\dfrac{q}{p} \\$
$\int^\infty_0 \dfrac{\cos(px) - \cos(qx)}{x^2}~dx = \dfrac{\pi(q-p)}{2}\\$
$\int^{2\pi}_0 \dfrac{dx}{a + b\,\sin x} = \dfrac{2\pi}{\sqrt{a^2-b^2}} \\$
$\int^{2\pi}_0 \dfrac{dx}{a + b\,\cos(x)} = \dfrac{2\pi}{\sqrt{a^2-b^2}} \\$
$\int^\infty_0 \dfrac{\sin x}{\sqrt{x}}~ dx =
\int^\infty_0 \dfrac{\cos x}{\sqrt{x}} dx =
\sqrt{\dfrac{\pi}{2}} \\$
$\int^\infty_0 \dfrac{\sin^3x}{x^3}~ dx = \dfrac{3\pi}{8}\\$
$\int^\infty_0 \dfrac{\sin^4x}{x^4}~ dx = \dfrac{\pi}{3}\\$
$\int^\infty_0 \dfrac{\tan x}{x} ~dx = \dfrac{\pi}{2}\\$
$\int^{\pi/2}_0 \dfrac{dx}{a + b\,\cos x} = \dfrac{\arccos(b/a)}{\sqrt{a^2-b^2}}\\$
$\int^\pi_0 \sin (mx) \cdot \sin (nx)\,dx = \left\{
\begin{array}{l l}
0 & \quad m , n \text{ integers and } m\ne n \\
\pi/2 & \quad m , n \text{ integers and } m = n
\end{array} \right.\\$
$\int^\pi_0 \cos (mx) \cdot \cos (nx)\,dx = \left\{
\begin{array}{l l}
0 & \quad m , n \text{ integers and } m\ne n \\
\pi/2 & \quad m , n \text{ integers and } m = n
\end{array} \right.\\$
$\int^\pi_0 \sin (mx) \cdot \cos (nx)\,dx = \left\{
\begin{array}{l l}
0 & \quad m , n \text{ integers and } m + n \text{ odd} \\
2m/(m^2 - n^2) & \quad m , n \text{ integers and } m + n \text{ even}
\end{array} \right.\\$
$\int^{\pi/2}_0 \sin^{2m}x\,dx = \int^{\pi/2}_0 \cos^{2m}x\,dx =
\dfrac{1\cdot3\cdot5\dots 2m-1}{2\cdot 4 \cdot 6 \dots 2m} \dfrac{\pi}{2}\\$
$\int^{\pi/2}_0 \sin^{2m+1}x\,dx = \int^{\pi/2}_0 \cos^{2m+1}x\,dx =
\dfrac{2\cdot 4 \cdot 6 \dots 2m}{1 \cdot 3 \cdot 5 \dots 2m + 1}\\$
$\int^{\pi/2}_0 \sin^{2m+1}x\,dx = \int^{\pi/2}_0 \cos^{2m+1}x\,dx =
\dfrac{2\cdot 4 \cdot 6 \dots 2m}{1 \cdot 3 \cdot 5 \dots 2m + 1}\\$
$\int^{\pi/2}_0 \sin^{2m+1}x\,dx = \int^{\pi/2}_0 \cos^{2m+1}x\,dx =
\dfrac{2\cdot 4 \cdot 6 \dots 2m}{1 \cdot 3 \cdot 5 \dots 2m + 1}\\$
$\int^{\pi}_0 \sin^{2p-1}x\,\cos^{2q-1}x\,dx = \dfrac{\Gamma(p)\,\Gamma{q}}{2\,\Gamma(p+q)}\\$
$\int^\infty_0 \dfrac{\sin (px) \cdot \cos (qx)}{x} \,dx = \left\{
\begin{array}{l l l}
~0 & p > q >0 \\
\pi/2 & 0 < p < q \\
\pi/4 & p = q > 0 \\
\end{array} \right.\\$
$\int^\infty_0 \dfrac{\sin (px) \cdot \sin (qx)}{x^2} \,dx = \left\{
\begin{array}{l l l}
\pi\,p/2 & 0 < p \le q \\
\pi\,q/2 & p \ge q > 0 \\
\end{array} \right.\\$
$\int^\infty_0 \dfrac{\cos (mx)}{x^2 + a^2}dx = \dfrac{\pi}{2a}~e^{-ma}\\$
$\int^\infty_0 \dfrac{x\,\sin (mx)}{x^2 + a^2} dx = \dfrac{\pi}{2}~e^{-ma}\\$
$\int^\infty_0 \dfrac{\sin (mx)}{x\left(x^2 + a^2\right)} dx = \dfrac{\pi}{2a^2}~\left(1-e^{-ma}\right)\\$
$\int^{2\pi}_0 \dfrac{dx}{(a + b\,\sin x)^2} =
\int^{2\pi}_0 \dfrac{dx}{(a + b\,\cos x)^2} =
\dfrac{2\pi\,a}{(a^2 - b^2)^{3/2}} \\$
$\int^{2\pi}_0 \dfrac{dx}{1 - 2a\,\cos x + a^2} =
\dfrac{2\pi}{1 - a^2}, ~ 0 < a < 1 \\$
$\int^{\pi}_0 \dfrac{x\,\sin x\,dx}{1 - 2a\,\cos x + a^2} = \left\{
\begin{array}{l l l}
\dfrac{\pi}{a}~ ln(1+a) & |a| < 1 \\
\pi \, ln(1 + \dfrac{1}{a}) & |a| > 1 \\
\end{array} \right. \\$
$\int^{\pi}_0 \dfrac{\cos (mx)\,dx}{1 - 2a\,\cos x + a^2} = \dfrac{\pi a^m}{1 - a^2}, ~~ a^2 < 1\\$
$\int^\infty_0 \sin (ax^n)\,dx = \dfrac{1}{na^{1/n}}~ \Gamma(1/n)\,\sin \dfrac{\pi}{2n} , ~~ n > 1\\$
$\int^\infty_0 \cos (ax^n)\,dx = \dfrac{1}{na^{1/n}}~ \Gamma(1/n)\,\cos \dfrac{\pi}{2n} , ~~ n > 1\\$
$\int^\infty_0 \dfrac{\sin x}{x^p}~ dx = \dfrac{\pi}{2\,\Gamma(p)\, \sin (p\pi/2)}, ~~ 0 < p < 1\\$
$\int^\infty_0 \dfrac{\cos x}{x^p}~ dx = \dfrac{\pi}{2\,\Gamma(p)\, \cos (p\pi/2)}, ~~ 0 < p < 1\\$
$\int^\infty_0 \sin (ax^2)\,\cos (2bx) \, dx =
\dfrac{1}{2} \sqrt{\dfrac{\pi}{2a}} \left(\cos\dfrac{b^2}{a} - \sin \dfrac{b^2}{a} \right)\\$
$\int^\infty_0 \cos (ax^2)\,\cos (2bx) \, dx =
\dfrac{1}{2} \sqrt{\dfrac{\pi}{2a}} \left(\cos\dfrac{b^2}{a} + \sin \dfrac{b^2}{a} \right)\\$
$\int^\infty_0 \dfrac{dx}{1 + \tan^mx}~ dx = \dfrac{\pi}{4}$