Optimal. Leaf size=126 \[ \frac{x^3 e^{-b^2 x^2} \text{Erf}(b x)}{2 \sqrt{\pi } b}+\frac{3 x e^{-b^2 x^2} \text{Erf}(b x)}{4 \sqrt{\pi } b^3}-\frac{3 \text{Erf}(b x)^2}{16 b^4}+\frac{x^2 e^{-2 b^2 x^2}}{4 \pi b^2}+\frac{e^{-2 b^2 x^2}}{2 \pi b^4}+\frac{1}{4} x^4 \text{Erf}(b x)^2 \]
[Out]
________________________________________________________________________________________
Rubi [A] time = 0.181377, antiderivative size = 126, normalized size of antiderivative = 1., number of steps used = 8, number of rules used = 6, integrand size = 10, \(\frac{\text{number of rules}}{\text{integrand size}}\) = 0.6, Rules used = {6364, 6385, 6373, 30, 2209, 2212} \[ \frac{x^3 e^{-b^2 x^2} \text{Erf}(b x)}{2 \sqrt{\pi } b}+\frac{3 x e^{-b^2 x^2} \text{Erf}(b x)}{4 \sqrt{\pi } b^3}-\frac{3 \text{Erf}(b x)^2}{16 b^4}+\frac{x^2 e^{-2 b^2 x^2}}{4 \pi b^2}+\frac{e^{-2 b^2 x^2}}{2 \pi b^4}+\frac{1}{4} x^4 \text{Erf}(b x)^2 \]
Antiderivative was successfully verified.
[In]
[Out]
Rule 6364
Rule 6385
Rule 6373
Rule 30
Rule 2209
Rule 2212
Rubi steps
\begin{align*} \int x^3 \text{erf}(b x)^2 \, dx &=\frac{1}{4} x^4 \text{erf}(b x)^2-\frac{b \int e^{-b^2 x^2} x^4 \text{erf}(b x) \, dx}{\sqrt{\pi }}\\ &=\frac{e^{-b^2 x^2} x^3 \text{erf}(b x)}{2 b \sqrt{\pi }}+\frac{1}{4} x^4 \text{erf}(b x)^2-\frac{\int e^{-2 b^2 x^2} x^3 \, dx}{\pi }-\frac{3 \int e^{-b^2 x^2} x^2 \text{erf}(b x) \, dx}{2 b \sqrt{\pi }}\\ &=\frac{e^{-2 b^2 x^2} x^2}{4 b^2 \pi }+\frac{3 e^{-b^2 x^2} x \text{erf}(b x)}{4 b^3 \sqrt{\pi }}+\frac{e^{-b^2 x^2} x^3 \text{erf}(b x)}{2 b \sqrt{\pi }}+\frac{1}{4} x^4 \text{erf}(b x)^2-\frac{\int e^{-2 b^2 x^2} x \, dx}{2 b^2 \pi }-\frac{3 \int e^{-2 b^2 x^2} x \, dx}{2 b^2 \pi }-\frac{3 \int e^{-b^2 x^2} \text{erf}(b x) \, dx}{4 b^3 \sqrt{\pi }}\\ &=\frac{e^{-2 b^2 x^2}}{2 b^4 \pi }+\frac{e^{-2 b^2 x^2} x^2}{4 b^2 \pi }+\frac{3 e^{-b^2 x^2} x \text{erf}(b x)}{4 b^3 \sqrt{\pi }}+\frac{e^{-b^2 x^2} x^3 \text{erf}(b x)}{2 b \sqrt{\pi }}+\frac{1}{4} x^4 \text{erf}(b x)^2-\frac{3 \operatorname{Subst}(\int x \, dx,x,\text{erf}(b x))}{8 b^4}\\ &=\frac{e^{-2 b^2 x^2}}{2 b^4 \pi }+\frac{e^{-2 b^2 x^2} x^2}{4 b^2 \pi }+\frac{3 e^{-b^2 x^2} x \text{erf}(b x)}{4 b^3 \sqrt{\pi }}+\frac{e^{-b^2 x^2} x^3 \text{erf}(b x)}{2 b \sqrt{\pi }}-\frac{3 \text{erf}(b x)^2}{16 b^4}+\frac{1}{4} x^4 \text{erf}(b x)^2\\ \end{align*}
Mathematica [A] time = 0.0350976, size = 90, normalized size = 0.71 \[ \frac{e^{-2 b^2 x^2} \left (4 \sqrt{\pi } b x e^{b^2 x^2} \left (2 b^2 x^2+3\right ) \text{Erf}(b x)+\pi e^{2 b^2 x^2} \left (4 b^4 x^4-3\right ) \text{Erf}(b x)^2+4 b^2 x^2+8\right )}{16 \pi b^4} \]
Antiderivative was successfully verified.
[In]
[Out]
________________________________________________________________________________________
Maple [F] time = 0.053, size = 0, normalized size = 0. \begin{align*} \int{x}^{3} \left ({\it Erf} \left ( bx \right ) \right ) ^{2}\, dx \end{align*}
Verification of antiderivative is not currently implemented for this CAS.
[In]
[Out]
________________________________________________________________________________________
Maxima [F] time = 0., size = 0, normalized size = 0. \begin{align*} -\frac{-\frac{{\left (2 \, b^{2} x^{2} + 1\right )} e^{\left (-2 \, b^{2} x^{2}\right )}}{4 \, b^{2}} - \frac{3 \, e^{\left (-2 \, b^{2} x^{2}\right )}}{4 \, b^{2}}}{2 \, \pi b^{2}} - \frac{{\left (3 \, \pi - 4 \, \pi b^{4} x^{4}\right )} \operatorname{erf}\left (b x\right )^{2} - 4 \,{\left (2 \, \sqrt{\pi } b^{3} x^{3} + 3 \, \sqrt{\pi } b x\right )} \operatorname{erf}\left (b x\right ) e^{\left (-b^{2} x^{2}\right )}}{16 \, \pi b^{4}} \end{align*}
Verification of antiderivative is not currently implemented for this CAS.
[In]
[Out]
________________________________________________________________________________________
Fricas [A] time = 2.96057, size = 186, normalized size = 1.48 \begin{align*} \frac{4 \, \sqrt{\pi }{\left (2 \, b^{3} x^{3} + 3 \, b x\right )} \operatorname{erf}\left (b x\right ) e^{\left (-b^{2} x^{2}\right )} -{\left (3 \, \pi - 4 \, \pi b^{4} x^{4}\right )} \operatorname{erf}\left (b x\right )^{2} + 4 \,{\left (b^{2} x^{2} + 2\right )} e^{\left (-2 \, b^{2} x^{2}\right )}}{16 \, \pi b^{4}} \end{align*}
Verification of antiderivative is not currently implemented for this CAS.
[In]
[Out]
________________________________________________________________________________________
Sympy [A] time = 5.43399, size = 117, normalized size = 0.93 \begin{align*} \begin{cases} \frac{x^{4} \operatorname{erf}^{2}{\left (b x \right )}}{4} + \frac{x^{3} e^{- b^{2} x^{2}} \operatorname{erf}{\left (b x \right )}}{2 \sqrt{\pi } b} + \frac{x^{2} e^{- 2 b^{2} x^{2}}}{4 \pi b^{2}} + \frac{3 x e^{- b^{2} x^{2}} \operatorname{erf}{\left (b x \right )}}{4 \sqrt{\pi } b^{3}} - \frac{3 \operatorname{erf}^{2}{\left (b x \right )}}{16 b^{4}} + \frac{e^{- 2 b^{2} x^{2}}}{2 \pi b^{4}} & \text{for}\: b \neq 0 \\0 & \text{otherwise} \end{cases} \end{align*}
Verification of antiderivative is not currently implemented for this CAS.
[In]
[Out]
________________________________________________________________________________________
Giac [F] time = 0., size = 0, normalized size = 0. \begin{align*} \int x^{3} \operatorname{erf}\left (b x\right )^{2}\,{d x} \end{align*}
Verification of antiderivative is not currently implemented for this CAS.
[In]
[Out]