List of integrals of irrational functions
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The following is a list of integrals (antiderivative functions) of irrational functions. For a complete list of integral functions, see lists of integrals. Throughout this article the constant of integration is omitted for brevity.
Integrals involving ''r'' = {{sqrt|''a''<sup>2</sup> + ''x''<sup>2</sup>}}
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Integrals involving ''s'' = {{sqrt|''x''<sup>2</sup> − ''a''<sup>2</sup>}}
Assume x2 > a2 (for x2 < a2, see next section):
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=\operatorname{sgn}(x)\,\operatorname{arcosh}\left|\frac{x}{a}\right|
=\frac{1}{2}\ln\left(\frac{x+s}{x-s}\right)\,, where the positive value of is to be taken.
= -\frac{1}{2n-1}\frac{x^{2m-1}}{s^{2n-1}}+\frac{2m-1}{2n-1}\int\frac{x^{2m-2}\,dx}{s^{2n-1}}
= \frac{xs}{2}+\frac{a^2}{2}\ln\left|\frac{x+s}{a}\right|
= -\frac{x}{s}+\ln\left|\frac{x+s}{a}\right|
= \frac{x^3s}{4}+\frac{3}{8}a^2xs+\frac{3}{8}a^4\ln\left|\frac{x+s}{a}\right|
= \frac{xs}{2}-\frac{a^2x}{s}+\frac{3}{2}a^2\ln\left|\frac{x+s}{a}\right|
= -\frac{x}{s}-\frac{1}{3}\frac{x^3}{s^3}+\ln\left|\frac{x+s}{a}\right|
= (-1)^{n-m}\frac{1}{a^{2(n-m)}}\sum_{i=0}^{n-m-1}\frac{1}{2(m+i)+1}{n-m-1 \choose i}\frac{x^{2(m+i)+1}}{s^{2(m+i)+1}}\qquad\mbox{(}n>m\ge0\mbox{)}
=-\frac{1}{a^6}\left[\frac{x}{s}-\frac{2}{3}\frac{x^3}{s^3}+\frac{1}{5}\frac{x^5}{s^5}\right]
=\frac{1}{a^8}\left[\frac{x}{s}-\frac{3}{3}\frac{x^3}{s^3}+\frac{3}{5}\frac{x^5}{s^5}-\frac{1}{7}\frac{x^7}{s^7}\right]
= \frac{1}{a^4}\left[\frac{1}{3}\frac{x^3}{s^3}-\frac{1}{5}\frac{x^5}{s^5}\right]
= -\frac{1}{a^6}\left[\frac{1}{3}\frac{x^3}{s^3}-\frac{2}{5}\frac{x^5}{s^5}+\frac{1}{7}\frac{x^7}{s^7}\right]
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Integrals involving ''u'' = {{sqrt|''a''<sup>2</sup> − ''x''<sup>2</sup>}}
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Integrals involving ''R'' = {{sqrt|''ax''<sup>2</sup> + ''bx'' + ''c''}}
Assume (ax2 + bx + c) cannot be reduced to the following expression (px + q)2 for some p and q.
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Integrals involving ''S'' = {{sqrt|''ax'' + ''b''}}
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\begin{cases}
-\dfrac{2}{\sqrt{b}} \operatorname{arcoth}\left( \dfrac{S}{\sqrt{b}}\right) & \mbox{(for }b > 0, \quad a x > 0\mbox{)} \\
-\dfrac{2}{\sqrt{b}} \operatorname{artanh}\left( \dfrac{S}{\sqrt{b}}\right) & \mbox{(for }b > 0, \quad a x < 0\mbox{)} \\
\dfrac{2}{\sqrt{-b}} \arctan\left( \dfrac{S}{\sqrt{-b}}\right) & \mbox{(for }b < 0\mbox{)} \\
\end{cases}
\begin{cases}
2 \left( S - \sqrt{b}\,\operatorname{arcoth}\left( \dfrac{S}{\sqrt{b}}\right)\right) & \mbox{(for }b > 0, \quad a x > 0\mbox{)} \\
2 \left( S - \sqrt{b}\,\operatorname{artanh}\left( \dfrac{S}{\sqrt{b}}\right)\right) & \mbox{(for }b > 0, \quad a x < 0\mbox{)} \\
2 \left( S - \sqrt{-b} \arctan\left( \dfrac{S}{\sqrt{-b}}\right)\right) & \mbox{(for }b < 0\mbox{)} \\
\end{cases}
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References
- {{cite book |editor1-last= Abramowitz |editor1-first= Milton |editor2-last= Stegun |editor2-first= Irene A. |date= 1972 |title= Handbook of Mathematical Functions with Formulas, Graphs, and Mathematical Tables |publisher= Dover |location= New York |chapter= Chapter 3 |chapter-url= http://www.math.sfu.ca/~cbm/aands/page_13.htm }}
- {{cite book |author-first1=Izrail Solomonovich |author-last1=Gradshteyn |author-link1=Izrail Solomonovich Gradshteyn |author-first2=Iosif Moiseevich |author-last2=Ryzhik |author-link2=Iosif Moiseevich Ryzhik |author-first3=Yuri Veniaminovich |author-last3=Geronimus |author-link3=Yuri Veniaminovich Geronimus |author-first4=Michail Yulyevich |author-last4=Tseytlin |author-link4=Michail Yulyevich Tseytlin |author-first5=Alan |author-last5=Jeffrey |editor-first1=Daniel |editor-last1=Zwillinger |editor-first2=Victor Hugo |editor-last2=Moll |editor-link2=Victor Hugo Moll |translator=Scripta Technica, Inc. |title=Table of Integrals, Series, and Products |publisher=Academic Press, Inc. |date=2015 |orig-year=October 2014 |edition=8 |language=en |isbn=978-0-12-384933-5 |lccn=2014010276 |title-link=Gradshteyn and Ryzhik}} (Several previous editions as well.)
- {{cite book |last=Peirce |first=Benjamin Osgood |title=A Short Table of Integrals |orig-year=1899 |edition=3rd revised |date=1929 |publisher=Ginn and Co |location=Boston |pages=16–30 |chapter=Chapter 3 }}
{{Lists of integrals}}