Integrand size = 18, antiderivative size = 38 \[ \int \frac {x^3}{a+b x^4+c x^8} \, dx=-\frac {\text {arctanh}\left (\frac {b+2 c x^4}{\sqrt {b^2-4 a c}}\right )}{2 \sqrt {b^2-4 a c}} \]
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Time = 0.03 (sec) , antiderivative size = 38, normalized size of antiderivative = 1.00, number of steps used = 3, number of rules used = 3, \(\frac {\text {number of rules}}{\text {integrand size}}\) = 0.167, Rules used = {1366, 632, 212} \[ \int \frac {x^3}{a+b x^4+c x^8} \, dx=-\frac {\text {arctanh}\left (\frac {b+2 c x^4}{\sqrt {b^2-4 a c}}\right )}{2 \sqrt {b^2-4 a c}} \]
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Rule 212
Rule 632
Rule 1366
Rubi steps \begin{align*} \text {integral}& = \frac {1}{4} \text {Subst}\left (\int \frac {1}{a+b x+c x^2} \, dx,x,x^4\right ) \\ & = -\left (\frac {1}{2} \text {Subst}\left (\int \frac {1}{b^2-4 a c-x^2} \, dx,x,b+2 c x^4\right )\right ) \\ & = -\frac {\tanh ^{-1}\left (\frac {b+2 c x^4}{\sqrt {b^2-4 a c}}\right )}{2 \sqrt {b^2-4 a c}} \\ \end{align*}
Time = 0.01 (sec) , antiderivative size = 42, normalized size of antiderivative = 1.11 \[ \int \frac {x^3}{a+b x^4+c x^8} \, dx=\frac {\arctan \left (\frac {b+2 c x^4}{\sqrt {-b^2+4 a c}}\right )}{2 \sqrt {-b^2+4 a c}} \]
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Time = 0.05 (sec) , antiderivative size = 37, normalized size of antiderivative = 0.97
method | result | size |
default | \(\frac {\arctan \left (\frac {2 c \,x^{4}+b}{\sqrt {4 a c -b^{2}}}\right )}{2 \sqrt {4 a c -b^{2}}}\) | \(37\) |
risch | \(-\frac {\ln \left (\left (-b +\sqrt {-4 a c +b^{2}}\right ) x^{4}-2 a \right )}{4 \sqrt {-4 a c +b^{2}}}+\frac {\ln \left (\left (b +\sqrt {-4 a c +b^{2}}\right ) x^{4}+2 a \right )}{4 \sqrt {-4 a c +b^{2}}}\) | \(70\) |
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none
Time = 0.26 (sec) , antiderivative size = 129, normalized size of antiderivative = 3.39 \[ \int \frac {x^3}{a+b x^4+c x^8} \, dx=\left [\frac {\log \left (\frac {2 \, c^{2} x^{8} + 2 \, b c x^{4} + b^{2} - 2 \, a c - {\left (2 \, c x^{4} + b\right )} \sqrt {b^{2} - 4 \, a c}}{c x^{8} + b x^{4} + a}\right )}{4 \, \sqrt {b^{2} - 4 \, a c}}, -\frac {\sqrt {-b^{2} + 4 \, a c} \arctan \left (-\frac {{\left (2 \, c x^{4} + b\right )} \sqrt {-b^{2} + 4 \, a c}}{b^{2} - 4 \, a c}\right )}{2 \, {\left (b^{2} - 4 \, a c\right )}}\right ] \]
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Leaf count of result is larger than twice the leaf count of optimal. 131 vs. \(2 (36) = 72\).
Time = 0.44 (sec) , antiderivative size = 131, normalized size of antiderivative = 3.45 \[ \int \frac {x^3}{a+b x^4+c x^8} \, dx=- \frac {\sqrt {- \frac {1}{4 a c - b^{2}}} \log {\left (x^{4} + \frac {- 4 a c \sqrt {- \frac {1}{4 a c - b^{2}}} + b^{2} \sqrt {- \frac {1}{4 a c - b^{2}}} + b}{2 c} \right )}}{4} + \frac {\sqrt {- \frac {1}{4 a c - b^{2}}} \log {\left (x^{4} + \frac {4 a c \sqrt {- \frac {1}{4 a c - b^{2}}} - b^{2} \sqrt {- \frac {1}{4 a c - b^{2}}} + b}{2 c} \right )}}{4} \]
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Exception generated. \[ \int \frac {x^3}{a+b x^4+c x^8} \, dx=\text {Exception raised: ValueError} \]
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Time = 1.66 (sec) , antiderivative size = 36, normalized size of antiderivative = 0.95 \[ \int \frac {x^3}{a+b x^4+c x^8} \, dx=\frac {\arctan \left (\frac {2 \, c x^{4} + b}{\sqrt {-b^{2} + 4 \, a c}}\right )}{2 \, \sqrt {-b^{2} + 4 \, a c}} \]
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Time = 8.21 (sec) , antiderivative size = 260, normalized size of antiderivative = 6.84 \[ \int \frac {x^3}{a+b x^4+c x^8} \, dx=-\frac {\mathrm {atan}\left (\frac {{\left (4\,a\,c-b^2\right )}^2\,\left (\frac {\left (\frac {4\,a\,c^4}{4\,a\,c-b^2}-\frac {4\,a\,b^2\,c^4}{{\left (4\,a\,c-b^2\right )}^2}\right )\,\left (b^3-3\,a\,b\,c\right )}{8\,a^3\,c^2\,\sqrt {4\,a\,c-b^2}}-x^4\,\left (\frac {\left (\frac {2\,c^4}{\sqrt {4\,a\,c-b^2}}-\frac {6\,b^2\,c^4}{{\left (4\,a\,c-b^2\right )}^{3/2}}\right )\,\left (a\,c-b^2\right )}{8\,a^3\,c^2}-\frac {\left (b^3-3\,a\,b\,c\right )\,\left (\frac {6\,b\,c^4}{4\,a\,c-b^2}-\frac {2\,b^3\,c^4}{{\left (4\,a\,c-b^2\right )}^2}\right )}{8\,a^3\,c^2\,\sqrt {4\,a\,c-b^2}}\right )+\frac {b\,c^2\,\left (a\,c-b^2\right )}{a^2\,{\left (4\,a\,c-b^2\right )}^{3/2}}\right )}{2\,c^4}\right )}{2\,\sqrt {4\,a\,c-b^2}} \]
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