Integrand size = 25, antiderivative size = 42 \[ \int \frac {\log \left (\frac {e}{e+f x}\right )}{e^2-f^2 x^2} \, dx=-\frac {\text {arctanh}\left (\frac {f x}{e}\right ) \log (2)}{e f}+\frac {\operatorname {PolyLog}\left (2,1-\frac {2 e}{e+f x}\right )}{2 e f} \]
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Time = 0.04 (sec) , antiderivative size = 42, normalized size of antiderivative = 1.00, number of steps used = 4, number of rules used = 4, \(\frac {\text {number of rules}}{\text {integrand size}}\) = 0.160, Rules used = {2450, 214, 2449, 2352} \[ \int \frac {\log \left (\frac {e}{e+f x}\right )}{e^2-f^2 x^2} \, dx=\frac {\operatorname {PolyLog}\left (2,1-\frac {2 e}{e+f x}\right )}{2 e f}-\frac {\log (2) \text {arctanh}\left (\frac {f x}{e}\right )}{e f} \]
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Rule 214
Rule 2352
Rule 2449
Rule 2450
Rubi steps \begin{align*} \text {integral}& = -\left (\log (2) \int \frac {1}{e^2-f^2 x^2} \, dx\right )+\int \frac {\log \left (\frac {2 e}{e+f x}\right )}{e^2-f^2 x^2} \, dx \\ & = -\frac {\tanh ^{-1}\left (\frac {f x}{e}\right ) \log (2)}{e f}+\frac {\text {Subst}\left (\int \frac {\log (2 e x)}{1-2 e x} \, dx,x,\frac {1}{e+f x}\right )}{f} \\ & = -\frac {\tanh ^{-1}\left (\frac {f x}{e}\right ) \log (2)}{e f}+\frac {\text {Li}_2\left (1-\frac {2 e}{e+f x}\right )}{2 e f} \\ \end{align*}
Time = 0.01 (sec) , antiderivative size = 81, normalized size of antiderivative = 1.93 \[ \int \frac {\log \left (\frac {e}{e+f x}\right )}{e^2-f^2 x^2} \, dx=-\frac {\log \left (\frac {e-f x}{2 e}\right ) \log \left (\frac {e}{e+f x}\right )}{2 e f}-\frac {\log ^2\left (\frac {e}{e+f x}\right )}{4 e f}+\frac {\operatorname {PolyLog}\left (2,\frac {e+f x}{2 e}\right )}{2 e f} \]
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Time = 0.62 (sec) , antiderivative size = 62, normalized size of antiderivative = 1.48
method | result | size |
derivativedivides | \(-\frac {\frac {\left (\ln \left (\frac {e}{f x +e}\right )-\ln \left (\frac {2 e}{f x +e}\right )\right ) \ln \left (1-\frac {2 e}{f x +e}\right )}{2}-\frac {\operatorname {dilog}\left (\frac {2 e}{f x +e}\right )}{2}}{f e}\) | \(62\) |
default | \(-\frac {\frac {\left (\ln \left (\frac {e}{f x +e}\right )-\ln \left (\frac {2 e}{f x +e}\right )\right ) \ln \left (1-\frac {2 e}{f x +e}\right )}{2}-\frac {\operatorname {dilog}\left (\frac {2 e}{f x +e}\right )}{2}}{f e}\) | \(62\) |
risch | \(-\frac {\ln \left (1-\frac {2 e}{f x +e}\right ) \ln \left (\frac {e}{f x +e}\right )}{2 e f}+\frac {\ln \left (1-\frac {2 e}{f x +e}\right ) \ln \left (\frac {2 e}{f x +e}\right )}{2 e f}+\frac {\operatorname {dilog}\left (\frac {2 e}{f x +e}\right )}{2 f e}\) | \(84\) |
parts | \(\frac {\ln \left (\frac {e}{f x +e}\right ) \ln \left (f x +e \right )}{2 e f}-\frac {\ln \left (\frac {e}{f x +e}\right ) \ln \left (-f x +e \right )}{2 e f}+\frac {f \left (\frac {\ln \left (f x +e \right )^{2}}{2 e \,f^{2}}+\frac {-\operatorname {dilog}\left (-\frac {-f x -e}{2 e}\right )-\ln \left (-f x +e \right ) \ln \left (-\frac {-f x -e}{2 e}\right )}{e \,f^{2}}\right )}{2}\) | \(118\) |
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\[ \int \frac {\log \left (\frac {e}{e+f x}\right )}{e^2-f^2 x^2} \, dx=\int { -\frac {\log \left (\frac {e}{f x + e}\right )}{f^{2} x^{2} - e^{2}} \,d x } \]
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\[ \int \frac {\log \left (\frac {e}{e+f x}\right )}{e^2-f^2 x^2} \, dx=- \int \frac {\log {\left (\frac {e}{e + f x} \right )}}{- e^{2} + f^{2} x^{2}}\, dx \]
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Leaf count of result is larger than twice the leaf count of optimal. 119 vs. \(2 (39) = 78\).
Time = 0.20 (sec) , antiderivative size = 119, normalized size of antiderivative = 2.83 \[ \int \frac {\log \left (\frac {e}{e+f x}\right )}{e^2-f^2 x^2} \, dx=\frac {1}{4} \, f {\left (\frac {\log \left (f x + e\right )^{2} - 2 \, \log \left (f x + e\right ) \log \left (f x - e\right )}{e f^{2}} + \frac {2 \, {\left (\log \left (f x + e\right ) \log \left (-\frac {f x + e}{2 \, e} + 1\right ) + {\rm Li}_2\left (\frac {f x + e}{2 \, e}\right )\right )}}{e f^{2}}\right )} + \frac {1}{2} \, {\left (\frac {\log \left (f x + e\right )}{e f} - \frac {\log \left (f x - e\right )}{e f}\right )} \log \left (\frac {e}{f x + e}\right ) \]
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\[ \int \frac {\log \left (\frac {e}{e+f x}\right )}{e^2-f^2 x^2} \, dx=\int { -\frac {\log \left (\frac {e}{f x + e}\right )}{f^{2} x^{2} - e^{2}} \,d x } \]
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Timed out. \[ \int \frac {\log \left (\frac {e}{e+f x}\right )}{e^2-f^2 x^2} \, dx=\int \frac {\ln \left (\frac {e}{e+f\,x}\right )}{e^2-f^2\,x^2} \,d x \]
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