Misplaced Pages

List of integrals of trigonometric functions

Article snapshot taken from Wikipedia with creative commons attribution-sharealike license. Give it a read and then ask your questions in the chat. We can research this topic together.

This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed.
Find sources: "List of integrals of trigonometric functions" – news · newspapers · books · scholar · JSTOR (April 2024) (Learn how and when to remove this message)
Trigonometry
Reference
Laws and theorems
Calculus
Mathematicians

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. For the special antiderivatives involving trigonometric functions, see Trigonometric integral.

Generally, if the function sin x {\displaystyle \sin x} is any trigonometric function, and cos x {\displaystyle \cos x} is its derivative,

a cos n x d x = a n sin n x + C {\displaystyle \int a\cos nx\,dx={\frac {a}{n}}\sin nx+C}

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

Integrands involving only sine

  • sin a x d x = 1 a cos a x + C {\displaystyle \int \sin ax\,dx=-{\frac {1}{a}}\cos ax+C}
  • sin 2 a x d x = x 2 1 4 a sin 2 a x + C = x 2 1 2 a sin a x cos a x + C {\displaystyle \int \sin ^{2}{ax}\,dx={\frac {x}{2}}-{\frac {1}{4a}}\sin 2ax+C={\frac {x}{2}}-{\frac {1}{2a}}\sin ax\cos ax+C}
  • sin 3 a x d x = cos 3 a x 12 a 3 cos a x 4 a + C {\displaystyle \int \sin ^{3}{ax}\,dx={\frac {\cos 3ax}{12a}}-{\frac {3\cos ax}{4a}}+C}
  • x sin 2 a x d x = x 2 4 x 4 a sin 2 a x 1 8 a 2 cos 2 a x + C {\displaystyle \int x\sin ^{2}{ax}\,dx={\frac {x^{2}}{4}}-{\frac {x}{4a}}\sin 2ax-{\frac {1}{8a^{2}}}\cos 2ax+C}
  • x 2 sin 2 a x d x = x 3 6 ( x 2 4 a 1 8 a 3 ) sin 2 a x x 4 a 2 cos 2 a x + C {\displaystyle \int x^{2}\sin ^{2}{ax}\,dx={\frac {x^{3}}{6}}-\left({\frac {x^{2}}{4a}}-{\frac {1}{8a^{3}}}\right)\sin 2ax-{\frac {x}{4a^{2}}}\cos 2ax+C}
  • x sin a x d x = sin a x a 2 x cos a x a + C {\displaystyle \int x\sin ax\,dx={\frac {\sin ax}{a^{2}}}-{\frac {x\cos ax}{a}}+C}
  • ( sin b 1 x ) ( sin b 2 x ) d x = sin ( ( b 2 b 1 ) x ) 2 ( b 2 b 1 ) sin ( ( b 1 + b 2 ) x ) 2 ( b 1 + b 2 ) + C (for  | b 1 | | b 2 | ) {\displaystyle \int (\sin b_{1}x)(\sin b_{2}x)\,dx={\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{)}}}
  • sin n a x d x = sin n 1 a x cos a x n a + n 1 n sin n 2 a x d x (for  n > 0 ) {\displaystyle \int \sin ^{n}{ax}\,dx=-{\frac {\sin ^{n-1}ax\cos ax}{na}}+{\frac {n-1}{n}}\int \sin ^{n-2}ax\,dx\qquad {\mbox{(for }}n>0{\mbox{)}}}
  • d x sin a x = 1 a ln | csc a x + cot a x | + C {\displaystyle \int {\frac {dx}{\sin ax}}=-{\frac {1}{a}}\ln {\left|\csc {ax}+\cot {ax}\right|}+C}
  • d x sin n a x = cos a x a ( 1 n ) sin n 1 a x + n 2 n 1 d x sin n 2 a x (for  n > 1 ) {\displaystyle \int {\frac {dx}{\sin ^{n}ax}}={\frac {\cos ax}{a(1-n)\sin ^{n-1}ax}}+{\frac {n-2}{n-1}}\int {\frac {dx}{\sin ^{n-2}ax}}\qquad {\mbox{(for }}n>1{\mbox{)}}}
  • x n sin a x d x = x n a cos a x + n a x n 1 cos a x d x = k = 0 2 k n ( 1 ) k + 1 x n 2 k a 1 + 2 k n ! ( n 2 k ) ! cos a x + k = 0 2 k + 1 n ( 1 ) k x n 1 2 k a 2 + 2 k n ! ( n 2 k 1 ) ! sin a x = k = 0 n x n k a 1 + k n ! ( n k ) ! cos ( a x + k π 2 ) (for  n > 0 ) {\displaystyle {\begin{aligned}\int x^{n}\sin ax\,dx&=-{\frac {x^{n}}{a}}\cos ax+{\frac {n}{a}}\int x^{n-1}\cos ax\,dx\\&=\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\\&=-\sum _{k=0}^{n}{\frac {x^{n-k}}{a^{1+k}}}{\frac {n!}{(n-k)!}}\cos \left(ax+k{\frac {\pi }{2}}\right)\qquad {\mbox{(for }}n>0{\mbox{)}}\end{aligned}}}
  • sin a x x d x = n = 0 ( 1 ) n ( a x ) 2 n + 1 ( 2 n + 1 ) ( 2 n + 1 ) ! + C {\displaystyle \int {\frac {\sin ax}{x}}\,dx=\sum _{n=0}^{\infty }(-1)^{n}{\frac {(ax)^{2n+1}}{(2n+1)\cdot (2n+1)!}}+C}
  • sin a x x n d x = sin a x ( n 1 ) x n 1 + a n 1 cos a x x n 1 d x {\displaystyle \int {\frac {\sin ax}{x^{n}}}\,dx=-{\frac {\sin ax}{(n-1)x^{n-1}}}+{\frac {a}{n-1}}\int {\frac {\cos ax}{x^{n-1}}}\,dx}
  • sin ( a x 2 + b x + c ) d x = { a π 2 cos ( b 2 4 a c 4 a ) S ( 2 a x + b 2 a π ) + a π 2 sin ( b 2 4 a c 4 a ) C ( 2 a x + b 2 a π ) t o b 2 4 a c > 0 a π 2 cos ( b 2 4 a c 4 a ) S ( 2 a x + b 2 a π ) a π 2 sin ( b 2 4 a c 4 a ) C ( 2 a x + b 2 a π ) t o b 2 4 a c < 0 f o r a = 0 , a > 0 {\displaystyle \int {\sin {\mathrm {(} }{ax}^{2}\mathrm {+} {bx}\mathrm {+} {c}{\mathrm {)} }{dx}}\mathrm {=} \left\{{\begin{aligned}&{{\sqrt {a}}{\sqrt {\frac {\mathit {\pi }}{2}}}\cos \left({\frac {{b}^{2}\mathrm {-} {4}{ac}}{4a}}\right){S}\left({\frac {{2}{ax}\mathrm {+} {b}}{\sqrt {{2}{a}{\mathit {\pi }}}}}\right)\mathrm {+} {\sqrt {a}}{\sqrt {\frac {\mathit {\pi }}{2}}}\sin \left({\frac {{b}^{2}\mathrm {-} {4}{ac}}{4a}}\right){C}\left({\frac {{2}{ax}\mathrm {+} {b}}{\sqrt {{2}{a}{\mathit {\pi }}}}}\right)\;{to}\;{b}^{2}\mathrm {-} {4}{ac}\;{\mathrm {>} }\;{0}}\\&{{\sqrt {a}}{\sqrt {\frac {\mathit {\pi }}{2}}}\cos \left({\frac {{b}^{2}\mathrm {-} {4}{ac}}{4a}}\right){S}\left({\frac {{2}{ax}\mathrm {+} {b}}{\sqrt {{2}{a}{\mathit {\pi }}}}}\right)\mathrm {-} {\sqrt {a}}{\sqrt {\frac {\mathit {\pi }}{2}}}\sin \left({\frac {{b}^{2}\mathrm {-} {4}{ac}}{4a}}\right){C}\left({\frac {{2}{ax}\mathrm {+} {b}}{\sqrt {{2}{a}{\mathit {\pi }}}}}\right)\;{to}\;{b}^{2}\mathrm {-} {4}{ac}\;{\mathrm {<} }\;{0}}\end{aligned}}\right.\;\;{for}\;{a}\diagup \!\!\!\!{\mathrm {=} }{0}{\mathrm {,} }\;{a}{\mathrm {>} }{0}}
  • d x 1 ± sin a x = 1 a tan ( a x 2 π 4 ) + C {\displaystyle \int {\frac {dx}{1\pm \sin ax}}={\frac {1}{a}}\tan \left({\frac {ax}{2}}\mp {\frac {\pi }{4}}\right)+C}
  • x d x 1 + sin a x = x a tan ( a x 2 π 4 ) + 2 a 2 ln | cos ( a x 2 π 4 ) | + C {\displaystyle \int {\frac {x\,dx}{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}
  • x d x 1 sin a x = x a cot ( π 4 a x 2 ) + 2 a 2 ln | sin ( π 4 a x 2 ) | + C {\displaystyle \int {\frac {x\,dx}{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}
  • sin a x d x 1 ± sin a x = ± x + 1 a tan ( π 4 a x 2 ) + C {\displaystyle \int {\frac {\sin ax\,dx}{1\pm \sin ax}}=\pm x+{\frac {1}{a}}\tan \left({\frac {\pi }{4}}\mp {\frac {ax}{2}}\right)+C}

Integrands involving only cosine

  • cos a x d x = 1 a sin a x + C {\displaystyle \int \cos ax\,dx={\frac {1}{a}}\sin ax+C}
  • cos 2 a x d x = x 2 + 1 4 a sin 2 a x + C = x 2 + 1 2 a sin a x cos a x + C {\displaystyle \int \cos ^{2}{ax}\,dx={\frac {x}{2}}+{\frac {1}{4a}}\sin 2ax+C={\frac {x}{2}}+{\frac {1}{2a}}\sin ax\cos ax+C}
  • cos n a x d x = cos n 1 a x sin a x n a + n 1 n cos n 2 a x d x (for  n > 0 ) {\displaystyle \int \cos ^{n}ax\,dx={\frac {\cos ^{n-1}ax\sin ax}{na}}+{\frac {n-1}{n}}\int \cos ^{n-2}ax\,dx\qquad {\mbox{(for }}n>0{\mbox{)}}}
  • x cos a x d x = cos a x a 2 + x sin a x a + C {\displaystyle \int x\cos ax\,dx={\frac {\cos ax}{a^{2}}}+{\frac {x\sin ax}{a}}+C}
  • x 2 cos 2 a x d x = x 3 6 + ( x 2 4 a 1 8 a 3 ) sin 2 a x + x 4 a 2 cos 2 a x + C {\displaystyle \int x^{2}\cos ^{2}{ax}\,dx={\frac {x^{3}}{6}}+\left({\frac {x^{2}}{4a}}-{\frac {1}{8a^{3}}}\right)\sin 2ax+{\frac {x}{4a^{2}}}\cos 2ax+C}
  • x n cos a x d x = x n sin a x a n a x n 1 sin a x d x = k = 0 2 k + 1 n ( 1 ) k x n 2 k 1 a 2 + 2 k n ! ( n 2 k 1 ) ! cos a x + k = 0 2 k n ( 1 ) k x n 2 k a 1 + 2 k n ! ( n 2 k ) ! sin a x = k = 0 n ( 1 ) k / 2 x n k a 1 + k n ! ( n k ) ! cos ( a x ( 1 ) k + 1 2 π 2 ) = k = 0 n x n k a 1 + k n ! ( n k ) ! sin ( a x + k π 2 ) (for  n > 0 ) {\displaystyle {\begin{aligned}\int x^{n}\cos ax\,dx&={\frac {x^{n}\sin ax}{a}}-{\frac {n}{a}}\int x^{n-1}\sin ax\,dx\\&=\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\\&=\sum _{k=0}^{n}(-1)^{\lfloor k/2\rfloor }{\frac {x^{n-k}}{a^{1+k}}}{\frac {n!}{(n-k)!}}\cos \left(ax-{\frac {(-1)^{k}+1}{2}}{\frac {\pi }{2}}\right)\\&=\sum _{k=0}^{n}{\frac {x^{n-k}}{a^{1+k}}}{\frac {n!}{(n-k)!}}\sin \left(ax+k{\frac {\pi }{2}}\right)\qquad {\mbox{(for }}n>0{\mbox{)}}\end{aligned}}}
  • cos a x x d x = ln | a x | + k = 1 ( 1 ) k ( a x ) 2 k 2 k ( 2 k ) ! + C {\displaystyle \int {\frac {\cos ax}{x}}\,dx=\ln |ax|+\sum _{k=1}^{\infty }(-1)^{k}{\frac {(ax)^{2k}}{2k\cdot (2k)!}}+C}
  • cos a x x n d x = cos a x ( n 1 ) x n 1 a n 1 sin a x x n 1 d x (for  n 1 ) {\displaystyle \int {\frac {\cos ax}{x^{n}}}\,dx=-{\frac {\cos ax}{(n-1)x^{n-1}}}-{\frac {a}{n-1}}\int {\frac {\sin ax}{x^{n-1}}}\,dx\qquad {\mbox{(for }}n\neq 1{\mbox{)}}}
  • d x cos a x = 1 a ln | tan ( a x 2 + π 4 ) | + C {\displaystyle \int {\frac {dx}{\cos ax}}={\frac {1}{a}}\ln \left|\tan \left({\frac {ax}{2}}+{\frac {\pi }{4}}\right)\right|+C}
  • d x cos n a x = sin a x a ( n 1 ) cos n 1 a x + n 2 n 1 d x cos n 2 a x (for  n > 1 ) {\displaystyle \int {\frac {dx}{\cos ^{n}ax}}={\frac {\sin ax}{a(n-1)\cos ^{n-1}ax}}+{\frac {n-2}{n-1}}\int {\frac {dx}{\cos ^{n-2}ax}}\qquad {\mbox{(for }}n>1{\mbox{)}}}
  • d x 1 + cos a x = 1 a tan a x 2 + C {\displaystyle \int {\frac {dx}{1+\cos ax}}={\frac {1}{a}}\tan {\frac {ax}{2}}+C}
  • d x 1 cos a x = 1 a cot a x 2 + C {\displaystyle \int {\frac {dx}{1-\cos ax}}=-{\frac {1}{a}}\cot {\frac {ax}{2}}+C}
  • x d x 1 + cos a x = x a tan a x 2 + 2 a 2 ln | cos a x 2 | + C {\displaystyle \int {\frac {x\,dx}{1+\cos ax}}={\frac {x}{a}}\tan {\frac {ax}{2}}+{\frac {2}{a^{2}}}\ln \left|\cos {\frac {ax}{2}}\right|+C}
  • x d x 1 cos a x = x a cot a x 2 + 2 a 2 ln | sin a x 2 | + C {\displaystyle \int {\frac {x\,dx}{1-\cos ax}}=-{\frac {x}{a}}\cot {\frac {ax}{2}}+{\frac {2}{a^{2}}}\ln \left|\sin {\frac {ax}{2}}\right|+C}
  • cos a x d x 1 + cos a x = x 1 a tan a x 2 + C {\displaystyle \int {\frac {\cos ax\,dx}{1+\cos ax}}=x-{\frac {1}{a}}\tan {\frac {ax}{2}}+C}
  • cos a x d x 1 cos a x = x 1 a cot a x 2 + C {\displaystyle \int {\frac {\cos ax\,dx}{1-\cos ax}}=-x-{\frac {1}{a}}\cot {\frac {ax}{2}}+C}
  • ( cos a 1 x ) ( cos a 2 x ) d x = sin ( ( a 2 a 1 ) x ) 2 ( a 2 a 1 ) + sin ( ( a 2 + a 1 ) x ) 2 ( a 2 + a 1 ) + C (for  | a 1 | | a 2 | ) {\displaystyle \int (\cos a_{1}x)(\cos a_{2}x)\,dx={\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

  • tan a x d x = 1 a ln | cos a x | + C = 1 a ln | sec a x | + C {\displaystyle \int \tan ax\,dx=-{\frac {1}{a}}\ln |\cos ax|+C={\frac {1}{a}}\ln |\sec ax|+C}
  • tan 2 x d x = tan x x + C {\displaystyle \int \tan ^{2}{x}\,dx=\tan {x}-x+C}
  • tan n a x d x = 1 a ( n 1 ) tan n 1 a x tan n 2 a x d x (for  n 1 ) {\displaystyle \int \tan ^{n}ax\,dx={\frac {1}{a(n-1)}}\tan ^{n-1}ax-\int \tan ^{n-2}ax\,dx\qquad {\mbox{(for }}n\neq 1{\mbox{)}}}
  • d x q tan a x + p = 1 p 2 + q 2 ( p x + q a ln | q sin a x + p cos a x | ) + C (for  p 2 + q 2 0 ) {\displaystyle \int {\frac {dx}{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{)}}}
  • d x tan a x ± 1 = ± x 2 + 1 2 a ln | sin a x ± cos a x | + C {\displaystyle \int {\frac {dx}{\tan ax\pm 1}}=\pm {\frac {x}{2}}+{\frac {1}{2a}}\ln |\sin ax\pm \cos ax|+C}
  • tan a x d x tan a x ± 1 = x 2 1 2 a ln | sin a x ± cos a x | + C {\displaystyle \int {\frac {\tan ax\,dx}{\tan ax\pm 1}}={\frac {x}{2}}\mp {\frac {1}{2a}}\ln |\sin ax\pm \cos ax|+C}

Integrands involving only secant

Further information: Integral of the secant function
  • sec a x d x = 1 a ln | sec a x + tan a x | + C = 1 a ln | tan ( a x 2 + π 4 ) | + C = 1 a artanh ( sin a x ) + C {\displaystyle \int \sec {ax}\,dx={\frac {1}{a}}\ln {\left|\sec {ax}+\tan {ax}\right|}+C={\frac {1}{a}}\ln {\left|\tan {\left({\frac {ax}{2}}+{\frac {\pi }{4}}\right)}\right|}+C={\frac {1}{a}}\operatorname {artanh} {\left(\sin {ax}\right)}+C}
  • sec 2 x d x = tan x + C {\displaystyle \int \sec ^{2}{x}\,dx=\tan {x}+C}
  • sec 3 x d x = 1 2 sec x tan x + 1 2 ln | sec x + tan x | + C . {\displaystyle \int \sec ^{3}{x}\,dx={\frac {1}{2}}\sec x\tan x+{\frac {1}{2}}\ln |\sec x+\tan x|+C.}
  • sec n a x d x = sec n 2 a x tan a x a ( n 1 ) + n 2 n 1 sec n 2 a x d x  (for  n 1 ) {\displaystyle \int \sec ^{n}{ax}\,dx={\frac {\sec ^{n-2}{ax}\tan {ax}}{a(n-1)}}\,+\,{\frac {n-2}{n-1}}\int \sec ^{n-2}{ax}\,dx\qquad {\mbox{ (for }}n\neq 1{\mbox{)}}}
  • d x sec x + 1 = x tan x 2 + C {\displaystyle \int {\frac {dx}{\sec {x}+1}}=x-\tan {\frac {x}{2}}+C}
  • d x sec x 1 = x cot x 2 + C {\displaystyle \int {\frac {dx}{\sec {x}-1}}=-x-\cot {\frac {x}{2}}+C}
  • sin x cos x = tan x {\displaystyle \int {\frac {\sin {x}}{\cos {x}}}=\int \tan {x}}

Integrands involving only cosecant

  • csc a x d x = 1 a ln | csc a x + cot a x | + C = 1 a ln | csc a x cot a x | + C = 1 a ln | tan ( a x 2 ) | + C {\displaystyle \int \csc {ax}\,dx=-{\frac {1}{a}}\ln {\left|\csc {ax}+\cot {ax}\right|}+C={\frac {1}{a}}\ln {\left|\csc {ax}-\cot {ax}\right|}+C={\frac {1}{a}}\ln {\left|\tan {\left({\frac {ax}{2}}\right)}\right|}+C}
  • csc 2 x d x = cot x + C {\displaystyle \int \csc ^{2}{x}\,dx=-\cot {x}+C}
  • csc 3 x d x = 1 2 csc x cot x 1 2 ln | csc x + cot x | + C = 1 2 csc x cot x + 1 2 ln | csc x cot x | + C {\displaystyle \int \csc ^{3}{x}\,dx=-{\frac {1}{2}}\csc x\cot x-{\frac {1}{2}}\ln |\csc x+\cot x|+C=-{\frac {1}{2}}\csc x\cot x+{\frac {1}{2}}\ln |\csc x-\cot x|+C}
  • csc n a x d x = csc n 2 a x cot a x a ( n 1 ) + n 2 n 1 csc n 2 a x d x  (for  n 1 ) {\displaystyle \int \csc ^{n}{ax}\,dx=-{\frac {\csc ^{n-2}{ax}\cot {ax}}{a(n-1)}}\,+\,{\frac {n-2}{n-1}}\int \csc ^{n-2}{ax}\,dx\qquad {\mbox{ (for }}n\neq 1{\mbox{)}}}
  • d x csc x + 1 = x 2 cot x 2 + 1 + C {\displaystyle \int {\frac {dx}{\csc {x}+1}}=x-{\frac {2}{\cot {\frac {x}{2}}+1}}+C}
  • d x csc x 1 = x + 2 cot x 2 1 + C {\displaystyle \int {\frac {dx}{\csc {x}-1}}=-x+{\frac {2}{\cot {\frac {x}{2}}-1}}+C}

Integrands involving only cotangent

  • cot a x d x = 1 a ln | sin a x | + C {\displaystyle \int \cot ax\,dx={\frac {1}{a}}\ln |\sin ax|+C}
  • cot 2 x d x = cot x x + C {\displaystyle \int \cot ^{2}{x}\,dx=-\cot {x}-x+C}
  • cot n a x d x = 1 a ( n 1 ) cot n 1 a x cot n 2 a x d x (for  n 1 ) {\displaystyle \int \cot ^{n}ax\,dx=-{\frac {1}{a(n-1)}}\cot ^{n-1}ax-\int \cot ^{n-2}ax\,dx\qquad {\mbox{(for }}n\neq 1{\mbox{)}}}
  • d x 1 + cot a x = tan a x d x tan a x + 1 = x 2 1 2 a ln | sin a x + cos a x | + C {\displaystyle \int {\frac {dx}{1+\cot ax}}=\int {\frac {\tan ax\,dx}{\tan ax+1}}={\frac {x}{2}}-{\frac {1}{2a}}\ln |\sin ax+\cos ax|+C}
  • d x 1 cot a x = tan a x d x tan a x 1 = x 2 + 1 2 a ln | sin a x cos a x | + C {\displaystyle \int {\frac {dx}{1-\cot ax}}=\int {\frac {\tan ax\,dx}{\tan ax-1}}={\frac {x}{2}}+{\frac {1}{2a}}\ln |\sin ax-\cos ax|+C}

Integrands involving both sine and cosine

An integral that is a rational function of the sine and cosine can be evaluated using Bioche's rules.

  • d x cos a x ± sin a x = 1 a 2 ln | tan ( a x 2 ± π 8 ) | + C {\displaystyle \int {\frac {dx}{\cos ax\pm \sin ax}}={\frac {1}{a{\sqrt {2}}}}\ln \left|\tan \left({\frac {ax}{2}}\pm {\frac {\pi }{8}}\right)\right|+C}
  • d x ( cos a x ± sin a x ) 2 = 1 2 a tan ( a x π 4 ) + C {\displaystyle \int {\frac {dx}{(\cos ax\pm \sin ax)^{2}}}={\frac {1}{2a}}\tan \left(ax\mp {\frac {\pi }{4}}\right)+C}
  • d x ( cos x + sin x ) n = 1 2 ( n 1 ) ( sin x cos x ( cos x + sin x ) n 1 + ( n 2 ) d x ( cos x + sin x ) n 2 ) {\displaystyle \int {\frac {dx}{(\cos x+\sin x)^{n}}}={\frac {1}{2(n-1)}}\left({\frac {\sin x-\cos x}{(\cos x+\sin x)^{n-1}}}+(n-2)\int {\frac {dx}{(\cos x+\sin x)^{n-2}}}\right)}
  • cos a x d x cos a x + sin a x = x 2 + 1 2 a ln | sin a x + cos a x | + C {\displaystyle \int {\frac {\cos ax\,dx}{\cos ax+\sin ax}}={\frac {x}{2}}+{\frac {1}{2a}}\ln \left|\sin ax+\cos ax\right|+C}
  • cos a x d x cos a x sin a x = x 2 1 2 a ln | sin a x cos a x | + C {\displaystyle \int {\frac {\cos ax\,dx}{\cos ax-\sin ax}}={\frac {x}{2}}-{\frac {1}{2a}}\ln \left|\sin ax-\cos ax\right|+C}
  • sin a x d x cos a x + sin a x = x 2 1 2 a ln | sin a x + cos a x | + C {\displaystyle \int {\frac {\sin ax\,dx}{\cos ax+\sin ax}}={\frac {x}{2}}-{\frac {1}{2a}}\ln \left|\sin ax+\cos ax\right|+C}
  • sin a x d x cos a x sin a x = x 2 1 2 a ln | sin a x cos a x | + C {\displaystyle \int {\frac {\sin ax\,dx}{\cos ax-\sin ax}}=-{\frac {x}{2}}-{\frac {1}{2a}}\ln \left|\sin ax-\cos ax\right|+C}
  • cos a x d x ( sin a x ) ( 1 + cos a x ) = 1 4 a tan 2 a x 2 + 1 2 a ln | tan a x 2 | + C {\displaystyle \int {\frac {\cos ax\,dx}{(\sin ax)(1+\cos ax)}}=-{\frac {1}{4a}}\tan ^{2}{\frac {ax}{2}}+{\frac {1}{2a}}\ln \left|\tan {\frac {ax}{2}}\right|+C}
  • cos a x d x ( sin a x ) ( 1 cos a x ) = 1 4 a cot 2 a x 2 1 2 a ln | tan a x 2 | + C {\displaystyle \int {\frac {\cos ax\,dx}{(\sin ax)(1-\cos ax)}}=-{\frac {1}{4a}}\cot ^{2}{\frac {ax}{2}}-{\frac {1}{2a}}\ln \left|\tan {\frac {ax}{2}}\right|+C}
  • sin a x d x ( cos a x ) ( 1 + sin a x ) = 1 4 a cot 2 ( a x 2 + π 4 ) + 1 2 a ln | tan ( a x 2 + π 4 ) | + C {\displaystyle \int {\frac {\sin ax\,dx}{(\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}
  • sin a x d x ( cos a x ) ( 1 sin a x ) = 1 4 a tan 2 ( a x 2 + π 4 ) 1 2 a ln | tan ( a x 2 + π 4 ) | + C {\displaystyle \int {\frac {\sin ax\,dx}{(\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}
  • ( sin a x ) ( cos a x ) d x = 1 2 a sin 2 a x + C {\displaystyle \int (\sin ax)(\cos ax)\,dx={\frac {1}{2a}}\sin ^{2}ax+C}
  • ( sin a 1 x ) ( cos a 2 x ) d x = cos ( ( a 1 a 2 ) x ) 2 ( a 1 a 2 ) cos ( ( a 1 + a 2 ) x ) 2 ( a 1 + a 2 ) + C (for  | a 1 | | a 2 | ) {\displaystyle \int (\sin a_{1}x)(\cos a_{2}x)\,dx=-{\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{)}}}
  • ( sin n a x ) ( cos a x ) d x = 1 a ( n + 1 ) sin n + 1 a x + C (for  n 1 ) {\displaystyle \int (\sin ^{n}ax)(\cos ax)\,dx={\frac {1}{a(n+1)}}\sin ^{n+1}ax+C\qquad {\mbox{(for }}n\neq -1{\mbox{)}}}
  • ( sin a x ) ( cos n a x ) d x = 1 a ( n + 1 ) cos n + 1 a x + C (for  n 1 ) {\displaystyle \int (\sin ax)(\cos ^{n}ax)\,dx=-{\frac {1}{a(n+1)}}\cos ^{n+1}ax+C\qquad {\mbox{(for }}n\neq -1{\mbox{)}}}
  • ( sin n a x ) ( cos m a x ) d x = ( sin n 1 a x ) ( cos m + 1 a x ) a ( n + m ) + n 1 n + m ( sin n 2 a x ) ( cos m a x ) d x (for  m , n > 0 ) = ( sin n + 1 a x ) ( cos m 1 a x ) a ( n + m ) + m 1 n + m ( sin n a x ) ( cos m 2 a x ) d x (for  m , n > 0 ) {\displaystyle {\begin{aligned}\int (\sin ^{n}ax)(\cos ^{m}ax)\,dx&=-{\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)\,dx\qquad {\mbox{(for }}m,n>0{\mbox{)}}\\&={\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)\,dx\qquad {\mbox{(for }}m,n>0{\mbox{)}}\end{aligned}}}
  • d x ( sin a x ) ( cos a x ) = 1 a ln | tan a x | + C {\displaystyle \int {\frac {dx}{(\sin ax)(\cos ax)}}={\frac {1}{a}}\ln \left|\tan ax\right|+C}
  • d x ( sin a x ) ( cos n a x ) = 1 a ( n 1 ) cos n 1 a x + d x ( sin a x ) ( cos n 2 a x ) (for  n 1 ) {\displaystyle \int {\frac {dx}{(\sin ax)(\cos ^{n}ax)}}={\frac {1}{a(n-1)\cos ^{n-1}ax}}+\int {\frac {dx}{(\sin ax)(\cos ^{n-2}ax)}}\qquad {\mbox{(for }}n\neq 1{\mbox{)}}}
  • d x ( sin n a x ) ( cos a x ) = 1 a ( n 1 ) sin n 1 a x + d x ( sin n 2 a x ) ( cos a x ) (for  n 1 ) {\displaystyle \int {\frac {dx}{(\sin ^{n}ax)(\cos ax)}}=-{\frac {1}{a(n-1)\sin ^{n-1}ax}}+\int {\frac {dx}{(\sin ^{n-2}ax)(\cos ax)}}\qquad {\mbox{(for }}n\neq 1{\mbox{)}}}
  • sin a x d x cos n a x = 1 a ( n 1 ) cos n 1 a x + C (for  n 1 ) {\displaystyle \int {\frac {\sin ax\,dx}{\cos ^{n}ax}}={\frac {1}{a(n-1)\cos ^{n-1}ax}}+C\qquad {\mbox{(for }}n\neq 1{\mbox{)}}}
  • sin 2 a x d x cos a x = 1 a sin a x + 1 a ln | tan ( π 4 + a x 2 ) | + C {\displaystyle \int {\frac {\sin ^{2}ax\,dx}{\cos ax}}=-{\frac {1}{a}}\sin ax+{\frac {1}{a}}\ln \left|\tan \left({\frac {\pi }{4}}+{\frac {ax}{2}}\right)\right|+C}
  • sin 2 a x d x cos n a x = sin a x a ( n 1 ) cos n 1 a x 1 n 1 d x cos n 2 a x (for  n 1 ) {\displaystyle \int {\frac {\sin ^{2}ax\,dx}{\cos ^{n}ax}}={\frac {\sin ax}{a(n-1)\cos ^{n-1}ax}}-{\frac {1}{n-1}}\int {\frac {dx}{\cos ^{n-2}ax}}\qquad {\mbox{(for }}n\neq 1{\mbox{)}}}
  • sin 2 x 1 + cos 2 x d x = 2 arctangant ( tan x 2 ) x (for x in ] π 2 ; + π 2 [ ) = 2 arctangant ( tan x 2 ) arctangant ( tan x ) (this time x being any real number  ) {\displaystyle {\begin{aligned}\int {\frac {\sin ^{2}x}{1+\cos ^{2}x}}\,dx&={\sqrt {2}}\operatorname {arctangant} \left({\frac {\tan x}{\sqrt {2}}}\right)-x\qquad {\mbox{(for x in}}]-{\frac {\pi }{2}};+{\frac {\pi }{2}}[{\mbox{)}}\\&={\sqrt {2}}\operatorname {arctangant} \left({\frac {\tan x}{\sqrt {2}}}\right)-\operatorname {arctangant} \left(\tan x\right)\qquad {\mbox{(this time x being any real number }}{\mbox{)}}\end{aligned}}}
  • sin n a x d x cos a x = sin n 1 a x a ( n 1 ) + sin n 2 a x d x cos a x (for  n 1 ) {\displaystyle \int {\frac {\sin ^{n}ax\,dx}{\cos ax}}=-{\frac {\sin ^{n-1}ax}{a(n-1)}}+\int {\frac {\sin ^{n-2}ax\,dx}{\cos ax}}\qquad {\mbox{(for }}n\neq 1{\mbox{)}}}
  • sin n a x d x cos m a x = { sin n + 1 a x a ( m 1 ) cos m 1 a x n m + 2 m 1 sin n a x d x cos m 2 a x (for  m 1 ) sin n 1 a x a ( m 1 ) cos m 1 a x n 1 m 1 sin n 2 a x d x cos m 2 a x (for  m 1 ) sin n 1 a x a ( n m ) cos m 1 a x + n 1 n m sin n 2 a x d x cos m a x (for  m n ) {\displaystyle \int {\frac {\sin ^{n}ax\,dx}{\cos ^{m}ax}}={\begin{cases}{\frac {\sin ^{n+1}ax}{a(m-1)\cos ^{m-1}ax}}-{\frac {n-m+2}{m-1}}\int {\frac {\sin ^{n}ax\,dx}{\cos ^{m-2}ax}}&{\mbox{(for }}m\neq 1{\mbox{)}}\\{\frac {\sin ^{n-1}ax}{a(m-1)\cos ^{m-1}ax}}-{\frac {n-1}{m-1}}\int {\frac {\sin ^{n-2}ax\,dx}{\cos ^{m-2}ax}}&{\mbox{(for }}m\neq 1{\mbox{)}}\\-{\frac {\sin ^{n-1}ax}{a(n-m)\cos ^{m-1}ax}}+{\frac {n-1}{n-m}}\int {\frac {\sin ^{n-2}ax\,dx}{\cos ^{m}ax}}&{\mbox{(for }}m\neq n{\mbox{)}}\end{cases}}}
  • cos a x d x sin n a x = 1 a ( n 1 ) sin n 1 a x + C (for  n 1 ) {\displaystyle \int {\frac {\cos ax\,dx}{\sin ^{n}ax}}=-{\frac {1}{a(n-1)\sin ^{n-1}ax}}+C\qquad {\mbox{(for }}n\neq 1{\mbox{)}}}
  • cos 2 a x d x sin a x = 1 a ( cos a x + ln | tan a x 2 | ) + C {\displaystyle \int {\frac {\cos ^{2}ax\,dx}{\sin ax}}={\frac {1}{a}}\left(\cos ax+\ln \left|\tan {\frac {ax}{2}}\right|\right)+C}
  • cos 2 a x d x sin n a x = 1 n 1 ( cos a x a sin n 1 a x + d x sin n 2 a x ) (for  n 1 ) {\displaystyle \int {\frac {\cos ^{2}ax\,dx}{\sin ^{n}ax}}=-{\frac {1}{n-1}}\left({\frac {\cos ax}{a\sin ^{n-1}ax}}+\int {\frac {dx}{\sin ^{n-2}ax}}\right)\qquad {\mbox{(for }}n\neq 1{\mbox{)}}}
  • cos n a x d x sin m a x = { cos n + 1 a x a ( m 1 ) sin m 1 a x n m + 2 m 1 cos n a x d x sin m 2 a x (for  n 1 ) cos n 1 a x a ( m 1 ) sin m 1 a x n 1 m 1 cos n 2 a x d x sin m 2 a x (for  m 1 ) cos n 1 a x a ( n m ) sin m 1 a x + n 1 n m cos n 2 a x d x sin m a x (for  m n ) {\displaystyle \int {\frac {\cos ^{n}ax\,dx}{\sin ^{m}ax}}={\begin{cases}-{\frac {\cos ^{n+1}ax}{a(m-1)\sin ^{m-1}ax}}-{\frac {n-m+2}{m-1}}\int {\frac {\cos ^{n}ax\,dx}{\sin ^{m-2}ax}}&{\mbox{(for }}n\neq 1{\mbox{)}}\\-{\frac {\cos ^{n-1}ax}{a(m-1)\sin ^{m-1}ax}}-{\frac {n-1}{m-1}}\int {\frac {\cos ^{n-2}ax\,dx}{\sin ^{m-2}ax}}&{\mbox{(for }}m\neq 1{\mbox{)}}\\{\frac {\cos ^{n-1}ax}{a(n-m)\sin ^{m-1}ax}}+{\frac {n-1}{n-m}}\int {\frac {\cos ^{n-2}ax\,dx}{\sin ^{m}ax}}&{\mbox{(for }}m\neq n{\mbox{)}}\end{cases}}}

Integrands involving both sine and tangent

  • ( sin a x ) ( tan a x ) d x = 1 a ( ln | sec a x + tan a x | sin a x ) + C {\displaystyle \int (\sin ax)(\tan ax)\,dx={\frac {1}{a}}(\ln |\sec ax+\tan ax|-\sin ax)+C}
  • tan n a x d x sin 2 a x = 1 a ( n 1 ) tan n 1 ( a x ) + C (for  n 1 ) {\displaystyle \int {\frac {\tan ^{n}ax\,dx}{\sin ^{2}ax}}={\frac {1}{a(n-1)}}\tan ^{n-1}(ax)+C\qquad {\mbox{(for }}n\neq 1{\mbox{)}}}

Integrand involving both cosine and tangent

  • tan n a x d x cos 2 a x = 1 a ( n + 1 ) tan n + 1 a x + C (for  n 1 ) {\displaystyle \int {\frac {\tan ^{n}ax\,dx}{\cos ^{2}ax}}={\frac {1}{a(n+1)}}\tan ^{n+1}ax+C\qquad {\mbox{(for }}n\neq -1{\mbox{)}}}

Integrand involving both sine and cotangent

  • cot n a x d x sin 2 a x = 1 a ( n + 1 ) cot n + 1 a x + C (for  n 1 ) {\displaystyle \int {\frac {\cot ^{n}ax\,dx}{\sin ^{2}ax}}=-{\frac {1}{a(n+1)}}\cot ^{n+1}ax+C\qquad {\mbox{(for }}n\neq -1{\mbox{)}}}

Integrand involving both cosine and cotangent

  • cot n a x d x cos 2 a x = 1 a ( 1 n ) tan 1 n a x + C (for  n 1 ) {\displaystyle \int {\frac {\cot ^{n}ax\,dx}{\cos ^{2}ax}}={\frac {1}{a(1-n)}}\tan ^{1-n}ax+C\qquad {\mbox{(for }}n\neq 1{\mbox{)}}}

Integrand involving both secant and tangent

  • ( sec x ) ( tan x ) d x = sec x + C {\displaystyle \int (\sec x)(\tan x)\,dx=\sec x+C}

Integrand involving both cosecant and cotangent

  • ( csc x ) ( cot x ) d x = csc x + C {\displaystyle \int (\csc x)(\cot x)\,dx=-\csc x+C}

Integrals in a quarter period

Using the beta function B ( a , b ) {\displaystyle B(a,b)} one can write

  • 0 π 2 sin n x d x = 0 π 2 cos n x d x = 1 2 B ( n + 1 2 , 1 2 ) = { n 1 n n 3 n 2 3 4 1 2 π 2 , if  n  is even n 1 n n 3 n 2 4 5 2 3 , if  n  is odd and more than 1 1 , if  n = 1 {\displaystyle \int _{0}^{\frac {\pi }{2}}\sin ^{n}x\,dx=\int _{0}^{\frac {\pi }{2}}\cos ^{n}x\,dx={\frac {1}{2}}B\left({\frac {n+1}{2}},{\frac {1}{2}}\right)={\begin{cases}{\frac {n-1}{n}}\cdot {\frac {n-3}{n-2}}\cdots {\frac {3}{4}}\cdot {\frac {1}{2}}\cdot {\frac {\pi }{2}},&{\text{if }}n{\text{ is even}}\\{\frac {n-1}{n}}\cdot {\frac {n-3}{n-2}}\cdots {\frac {4}{5}}\cdot {\frac {2}{3}},&{\text{if }}n{\text{ is odd and more than 1}}\\1,&{\text{if }}n=1\end{cases}}}

Integrals with symmetric limits

  • c c sin x d x = 0 {\displaystyle \int _{-c}^{c}\sin {x}\,dx=0}
  • c c cos x d x = 2 0 c cos x d x = 2 c 0 cos x d x = 2 sin c {\displaystyle \int _{-c}^{c}\cos {x}\,dx=2\int _{0}^{c}\cos {x}\,dx=2\int _{-c}^{0}\cos {x}\,dx=2\sin {c}}
  • c c tan x d x = 0 {\displaystyle \int _{-c}^{c}\tan {x}\,dx=0}
  • a 2 a 2 x 2 cos 2 n π x a d x = a 3 ( n 2 π 2 6 ) 24 n 2 π 2 (for  n = 1 , 3 , 5... ) {\displaystyle \int _{-{\frac {a}{2}}}^{\frac {a}{2}}x^{2}\cos ^{2}{\frac {n\pi x}{a}}\,dx={\frac {a^{3}(n^{2}\pi ^{2}-6)}{24n^{2}\pi ^{2}}}\qquad {\mbox{(for }}n=1,3,5...{\mbox{)}}}
  • a 2 a 2 x 2 sin 2 n π x a d x = a 3 ( n 2 π 2 6 ( 1 ) n ) 24 n 2 π 2 = a 3 24 ( 1 6 ( 1 ) n n 2 π 2 ) (for  n = 1 , 2 , 3 , . . . ) {\displaystyle \int _{\frac {-a}{2}}^{\frac {a}{2}}x^{2}\sin ^{2}{\frac {n\pi x}{a}}\,dx={\frac {a^{3}(n^{2}\pi ^{2}-6(-1)^{n})}{24n^{2}\pi ^{2}}}={\frac {a^{3}}{24}}(1-6{\frac {(-1)^{n}}{n^{2}\pi ^{2}}})\qquad {\mbox{(for }}n=1,2,3,...{\mbox{)}}}

Integral over a full circle

  • 0 2 π sin 2 m + 1 x cos n x d x = 0 n , m Z {\displaystyle \int _{0}^{2\pi }\sin ^{2m+1}{x}\cos ^{n}{x}\,dx=0\!\qquad n,m\in \mathbb {Z} }
  • 0 2 π sin m x cos 2 n + 1 x d x = 0 n , m Z {\displaystyle \int _{0}^{2\pi }\sin ^{m}{x}\cos ^{2n+1}{x}\,dx=0\!\qquad n,m\in \mathbb {Z} }

See also

References

  1. Bresock, Krista (2022-01-01). "Student Understanding of the Definite Integral When Solving Calculus Volume Problems". Graduate Theses, Dissertations, and Problem Reports. doi:10.33915/etd.11491.
Lists of integrals
Categories: