3.421 \(\int \frac{1}{x \sqrt [3]{a^3-b^3 x}} \, dx\)

Optimal. Leaf size=73 \[ \frac{3 \log \left (a-\sqrt [3]{a^3-b^3 x}\right )}{2 a}+\frac{\sqrt{3} \tan ^{-1}\left (\frac{2 \sqrt [3]{a^3-b^3 x}+a}{\sqrt{3} a}\right )}{a}-\frac{\log (x)}{2 a} \]

[Out]

(Sqrt[3]*ArcTan[(a + 2*(a^3 - b^3*x)^(1/3))/(Sqrt[3]*a)])/a - Log[x]/(2*a) + (3*Log[a - (a^3 - b^3*x)^(1/3)])/
(2*a)

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Rubi [A]  time = 0.030922, antiderivative size = 73, normalized size of antiderivative = 1., number of steps used = 4, number of rules used = 4, integrand size = 18, \(\frac{\text{number of rules}}{\text{integrand size}}\) = 0.222, Rules used = {55, 617, 204, 31} \[ \frac{3 \log \left (a-\sqrt [3]{a^3-b^3 x}\right )}{2 a}+\frac{\sqrt{3} \tan ^{-1}\left (\frac{2 \sqrt [3]{a^3-b^3 x}+a}{\sqrt{3} a}\right )}{a}-\frac{\log (x)}{2 a} \]

Antiderivative was successfully verified.

[In]

Int[1/(x*(a^3 - b^3*x)^(1/3)),x]

[Out]

(Sqrt[3]*ArcTan[(a + 2*(a^3 - b^3*x)^(1/3))/(Sqrt[3]*a)])/a - Log[x]/(2*a) + (3*Log[a - (a^3 - b^3*x)^(1/3)])/
(2*a)

Rule 55

Int[1/(((a_.) + (b_.)*(x_))*((c_.) + (d_.)*(x_))^(1/3)), x_Symbol] :> With[{q = Rt[(b*c - a*d)/b, 3]}, -Simp[L
og[RemoveContent[a + b*x, x]]/(2*b*q), x] + (Dist[3/(2*b), Subst[Int[1/(q^2 + q*x + x^2), x], x, (c + d*x)^(1/
3)], x] - Dist[3/(2*b*q), Subst[Int[1/(q - x), x], x, (c + d*x)^(1/3)], x])] /; FreeQ[{a, b, c, d}, x] && PosQ
[(b*c - a*d)/b]

Rule 617

Int[((a_) + (b_.)*(x_) + (c_.)*(x_)^2)^(-1), x_Symbol] :> With[{q = 1 - 4*Simplify[(a*c)/b^2]}, Dist[-2/b, Sub
st[Int[1/(q - x^2), x], x, 1 + (2*c*x)/b], x] /; RationalQ[q] && (EqQ[q^2, 1] ||  !RationalQ[b^2 - 4*a*c])] /;
FreeQ[{a, b, c}, x] && NeQ[b^2 - 4*a*c, 0]

Rule 204

Int[((a_) + (b_.)*(x_)^2)^(-1), x_Symbol] :> -Simp[ArcTan[(Rt[-b, 2]*x)/Rt[-a, 2]]/(Rt[-a, 2]*Rt[-b, 2]), x] /
; FreeQ[{a, b}, x] && PosQ[a/b] && (LtQ[a, 0] || LtQ[b, 0])

Rule 31

Int[((a_) + (b_.)*(x_))^(-1), x_Symbol] :> Simp[Log[RemoveContent[a + b*x, x]]/b, x] /; FreeQ[{a, b}, x]

Rubi steps

\begin{align*} \int \frac{1}{x \sqrt [3]{a^3-b^3 x}} \, dx &=-\frac{\log (x)}{2 a}+\frac{3}{2} \operatorname{Subst}\left (\int \frac{1}{a^2+a x+x^2} \, dx,x,\sqrt [3]{a^3-b^3 x}\right )-\frac{3 \operatorname{Subst}\left (\int \frac{1}{a-x} \, dx,x,\sqrt [3]{a^3-b^3 x}\right )}{2 a}\\ &=-\frac{\log (x)}{2 a}+\frac{3 \log \left (a-\sqrt [3]{a^3-b^3 x}\right )}{2 a}-\frac{3 \operatorname{Subst}\left (\int \frac{1}{-3-x^2} \, dx,x,1+\frac{2 \sqrt [3]{a^3-b^3 x}}{a}\right )}{a}\\ &=\frac{\sqrt{3} \tan ^{-1}\left (\frac{1+\frac{2 \sqrt [3]{a^3-b^3 x}}{a}}{\sqrt{3}}\right )}{a}-\frac{\log (x)}{2 a}+\frac{3 \log \left (a-\sqrt [3]{a^3-b^3 x}\right )}{2 a}\\ \end{align*}

Mathematica [A]  time = 0.0618446, size = 68, normalized size = 0.93 \[ \frac{3 \log \left (a-\sqrt [3]{a^3-b^3 x}\right )+2 \sqrt{3} \tan ^{-1}\left (\frac{2 \sqrt [3]{a^3-b^3 x}+a}{\sqrt{3} a}\right )-\log (x)}{2 a} \]

Antiderivative was successfully verified.

[In]

Integrate[1/(x*(a^3 - b^3*x)^(1/3)),x]

[Out]

(2*Sqrt[3]*ArcTan[(a + 2*(a^3 - b^3*x)^(1/3))/(Sqrt[3]*a)] - Log[x] + 3*Log[a - (a^3 - b^3*x)^(1/3)])/(2*a)

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Maple [A]  time = 0.005, size = 91, normalized size = 1.3 \begin{align*}{\frac{1}{a}\ln \left ( -a+\sqrt [3]{-{b}^{3}x+{a}^{3}} \right ) }-{\frac{1}{2\,a}\ln \left ( \left ( -{b}^{3}x+{a}^{3} \right ) ^{{\frac{2}{3}}}+a\sqrt [3]{-{b}^{3}x+{a}^{3}}+{a}^{2} \right ) }+{\frac{\sqrt{3}}{a}\arctan \left ({\frac{\sqrt{3}}{3\,a} \left ( a+2\,\sqrt [3]{-{b}^{3}x+{a}^{3}} \right ) } \right ) } \end{align*}

Verification of antiderivative is not currently implemented for this CAS.

[In]

int(1/x/(-b^3*x+a^3)^(1/3),x)

[Out]

1/a*ln(-a+(-b^3*x+a^3)^(1/3))-1/2/a*ln((-b^3*x+a^3)^(2/3)+a*(-b^3*x+a^3)^(1/3)+a^2)+arctan(1/3*(a+2*(-b^3*x+a^
3)^(1/3))/a*3^(1/2))*3^(1/2)/a

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Maxima [A]  time = 1.52501, size = 122, normalized size = 1.67 \begin{align*} \frac{\sqrt{3} \arctan \left (\frac{\sqrt{3}{\left (a + 2 \,{\left (-b^{3} x + a^{3}\right )}^{\frac{1}{3}}\right )}}{3 \, a}\right )}{a} - \frac{\log \left (a^{2} +{\left (-b^{3} x + a^{3}\right )}^{\frac{1}{3}} a +{\left (-b^{3} x + a^{3}\right )}^{\frac{2}{3}}\right )}{2 \, a} + \frac{\log \left (-a +{\left (-b^{3} x + a^{3}\right )}^{\frac{1}{3}}\right )}{a} \end{align*}

Verification of antiderivative is not currently implemented for this CAS.

[In]

integrate(1/x/(-b^3*x+a^3)^(1/3),x, algorithm="maxima")

[Out]

sqrt(3)*arctan(1/3*sqrt(3)*(a + 2*(-b^3*x + a^3)^(1/3))/a)/a - 1/2*log(a^2 + (-b^3*x + a^3)^(1/3)*a + (-b^3*x
+ a^3)^(2/3))/a + log(-a + (-b^3*x + a^3)^(1/3))/a

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Fricas [A]  time = 1.63676, size = 232, normalized size = 3.18 \begin{align*} \frac{2 \, \sqrt{3} \arctan \left (\frac{\sqrt{3} a + 2 \, \sqrt{3}{\left (-b^{3} x + a^{3}\right )}^{\frac{1}{3}}}{3 \, a}\right ) - \log \left (a^{2} +{\left (-b^{3} x + a^{3}\right )}^{\frac{1}{3}} a +{\left (-b^{3} x + a^{3}\right )}^{\frac{2}{3}}\right ) + 2 \, \log \left (-a +{\left (-b^{3} x + a^{3}\right )}^{\frac{1}{3}}\right )}{2 \, a} \end{align*}

Verification of antiderivative is not currently implemented for this CAS.

[In]

integrate(1/x/(-b^3*x+a^3)^(1/3),x, algorithm="fricas")

[Out]

1/2*(2*sqrt(3)*arctan(1/3*(sqrt(3)*a + 2*sqrt(3)*(-b^3*x + a^3)^(1/3))/a) - log(a^2 + (-b^3*x + a^3)^(1/3)*a +
(-b^3*x + a^3)^(2/3)) + 2*log(-a + (-b^3*x + a^3)^(1/3)))/a

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Sympy [C]  time = 2.40131, size = 136, normalized size = 1.86 \begin{align*} - \frac{e^{- \frac{2 i \pi }{3}} \log{\left (- \frac{a e^{\frac{i \pi }{3}}}{b \sqrt [3]{- \frac{a^{3}}{b^{3}} + x}} + 1 \right )} \Gamma \left (- \frac{1}{3}\right )}{3 a \Gamma \left (\frac{2}{3}\right )} + \frac{e^{- \frac{i \pi }{3}} \log{\left (- \frac{a e^{i \pi }}{b \sqrt [3]{- \frac{a^{3}}{b^{3}} + x}} + 1 \right )} \Gamma \left (- \frac{1}{3}\right )}{3 a \Gamma \left (\frac{2}{3}\right )} - \frac{\log{\left (- \frac{a e^{\frac{5 i \pi }{3}}}{b \sqrt [3]{- \frac{a^{3}}{b^{3}} + x}} + 1 \right )} \Gamma \left (- \frac{1}{3}\right )}{3 a \Gamma \left (\frac{2}{3}\right )} \end{align*}

Verification of antiderivative is not currently implemented for this CAS.

[In]

integrate(1/x/(-b**3*x+a**3)**(1/3),x)

[Out]

-exp(-2*I*pi/3)*log(-a*exp_polar(I*pi/3)/(b*(-a**3/b**3 + x)**(1/3)) + 1)*gamma(-1/3)/(3*a*gamma(2/3)) + exp(-
I*pi/3)*log(-a*exp_polar(I*pi)/(b*(-a**3/b**3 + x)**(1/3)) + 1)*gamma(-1/3)/(3*a*gamma(2/3)) - log(-a*exp_pola
r(5*I*pi/3)/(b*(-a**3/b**3 + x)**(1/3)) + 1)*gamma(-1/3)/(3*a*gamma(2/3))

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Giac [A]  time = 1.23209, size = 123, normalized size = 1.68 \begin{align*} \frac{\sqrt{3} \arctan \left (\frac{\sqrt{3}{\left (a + 2 \,{\left (-b^{3} x + a^{3}\right )}^{\frac{1}{3}}\right )}}{3 \, a}\right )}{a} - \frac{\log \left (a^{2} +{\left (-b^{3} x + a^{3}\right )}^{\frac{1}{3}} a +{\left (-b^{3} x + a^{3}\right )}^{\frac{2}{3}}\right )}{2 \, a} + \frac{\log \left ({\left | -a +{\left (-b^{3} x + a^{3}\right )}^{\frac{1}{3}} \right |}\right )}{a} \end{align*}

Verification of antiderivative is not currently implemented for this CAS.

[In]

integrate(1/x/(-b^3*x+a^3)^(1/3),x, algorithm="giac")

[Out]

sqrt(3)*arctan(1/3*sqrt(3)*(a + 2*(-b^3*x + a^3)^(1/3))/a)/a - 1/2*log(a^2 + (-b^3*x + a^3)^(1/3)*a + (-b^3*x
+ a^3)^(2/3))/a + log(abs(-a + (-b^3*x + a^3)^(1/3)))/a