3.2.80 \(\int \frac {1}{x^3 \sqrt {a x^2+b x^3}} \, dx\)

Optimal. Leaf size=115 \[ \frac {5 b^3 \tanh ^{-1}\left (\frac {\sqrt {a} x}{\sqrt {a x^2+b x^3}}\right )}{8 a^{7/2}}-\frac {5 b^2 \sqrt {a x^2+b x^3}}{8 a^3 x^2}+\frac {5 b \sqrt {a x^2+b x^3}}{12 a^2 x^3}-\frac {\sqrt {a x^2+b x^3}}{3 a x^4} \]

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Rubi [A]  time = 0.14, antiderivative size = 115, normalized size of antiderivative = 1.00, number of steps used = 5, number of rules used = 3, integrand size = 19, \(\frac {\text {number of rules}}{\text {integrand size}}\) = 0.158, Rules used = {2025, 2008, 206} \begin {gather*} -\frac {5 b^2 \sqrt {a x^2+b x^3}}{8 a^3 x^2}+\frac {5 b^3 \tanh ^{-1}\left (\frac {\sqrt {a} x}{\sqrt {a x^2+b x^3}}\right )}{8 a^{7/2}}+\frac {5 b \sqrt {a x^2+b x^3}}{12 a^2 x^3}-\frac {\sqrt {a x^2+b x^3}}{3 a x^4} \end {gather*}

Antiderivative was successfully verified.

[In]

Int[1/(x^3*Sqrt[a*x^2 + b*x^3]),x]

[Out]

-Sqrt[a*x^2 + b*x^3]/(3*a*x^4) + (5*b*Sqrt[a*x^2 + b*x^3])/(12*a^2*x^3) - (5*b^2*Sqrt[a*x^2 + b*x^3])/(8*a^3*x
^2) + (5*b^3*ArcTanh[(Sqrt[a]*x)/Sqrt[a*x^2 + b*x^3]])/(8*a^(7/2))

Rule 206

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

Rule 2008

Int[1/Sqrt[(a_.)*(x_)^2 + (b_.)*(x_)^(n_.)], x_Symbol] :> Dist[2/(2 - n), Subst[Int[1/(1 - a*x^2), x], x, x/Sq
rt[a*x^2 + b*x^n]], x] /; FreeQ[{a, b, n}, x] && NeQ[n, 2]

Rule 2025

Int[((c_.)*(x_))^(m_.)*((a_.)*(x_)^(j_.) + (b_.)*(x_)^(n_.))^(p_), x_Symbol] :> Simp[(c^(j - 1)*(c*x)^(m - j +
1)*(a*x^j + b*x^n)^(p + 1))/(a*(m + j*p + 1)), x] - Dist[(b*(m + n*p + n - j + 1))/(a*c^(n - j)*(m + j*p + 1)
), Int[(c*x)^(m + n - j)*(a*x^j + b*x^n)^p, x], x] /; FreeQ[{a, b, c, m, p}, x] &&  !IntegerQ[p] && LtQ[0, j,
n] && (IntegersQ[j, n] || GtQ[c, 0]) && LtQ[m + j*p + 1, 0]

Rubi steps

\begin {align*} \int \frac {1}{x^3 \sqrt {a x^2+b x^3}} \, dx &=-\frac {\sqrt {a x^2+b x^3}}{3 a x^4}-\frac {(5 b) \int \frac {1}{x^2 \sqrt {a x^2+b x^3}} \, dx}{6 a}\\ &=-\frac {\sqrt {a x^2+b x^3}}{3 a x^4}+\frac {5 b \sqrt {a x^2+b x^3}}{12 a^2 x^3}+\frac {\left (5 b^2\right ) \int \frac {1}{x \sqrt {a x^2+b x^3}} \, dx}{8 a^2}\\ &=-\frac {\sqrt {a x^2+b x^3}}{3 a x^4}+\frac {5 b \sqrt {a x^2+b x^3}}{12 a^2 x^3}-\frac {5 b^2 \sqrt {a x^2+b x^3}}{8 a^3 x^2}-\frac {\left (5 b^3\right ) \int \frac {1}{\sqrt {a x^2+b x^3}} \, dx}{16 a^3}\\ &=-\frac {\sqrt {a x^2+b x^3}}{3 a x^4}+\frac {5 b \sqrt {a x^2+b x^3}}{12 a^2 x^3}-\frac {5 b^2 \sqrt {a x^2+b x^3}}{8 a^3 x^2}+\frac {\left (5 b^3\right ) \operatorname {Subst}\left (\int \frac {1}{1-a x^2} \, dx,x,\frac {x}{\sqrt {a x^2+b x^3}}\right )}{8 a^3}\\ &=-\frac {\sqrt {a x^2+b x^3}}{3 a x^4}+\frac {5 b \sqrt {a x^2+b x^3}}{12 a^2 x^3}-\frac {5 b^2 \sqrt {a x^2+b x^3}}{8 a^3 x^2}+\frac {5 b^3 \tanh ^{-1}\left (\frac {\sqrt {a} x}{\sqrt {a x^2+b x^3}}\right )}{8 a^{7/2}}\\ \end {align*}

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Mathematica [C]  time = 0.01, size = 40, normalized size = 0.35 \begin {gather*} \frac {2 b^3 \sqrt {x^2 (a+b x)} \, _2F_1\left (\frac {1}{2},4;\frac {3}{2};\frac {b x}{a}+1\right )}{a^4 x} \end {gather*}

Antiderivative was successfully verified.

[In]

Integrate[1/(x^3*Sqrt[a*x^2 + b*x^3]),x]

[Out]

(2*b^3*Sqrt[x^2*(a + b*x)]*Hypergeometric2F1[1/2, 4, 3/2, 1 + (b*x)/a])/(a^4*x)

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IntegrateAlgebraic [A]  time = 0.07, size = 80, normalized size = 0.70 \begin {gather*} \frac {5 b^3 \tanh ^{-1}\left (\frac {\sqrt {a} x}{\sqrt {a x^2+b x^3}}\right )}{8 a^{7/2}}+\frac {\left (-8 a^2+10 a b x-15 b^2 x^2\right ) \sqrt {a x^2+b x^3}}{24 a^3 x^4} \end {gather*}

Antiderivative was successfully verified.

[In]

IntegrateAlgebraic[1/(x^3*Sqrt[a*x^2 + b*x^3]),x]

[Out]

((-8*a^2 + 10*a*b*x - 15*b^2*x^2)*Sqrt[a*x^2 + b*x^3])/(24*a^3*x^4) + (5*b^3*ArcTanh[(Sqrt[a]*x)/Sqrt[a*x^2 +
b*x^3]])/(8*a^(7/2))

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fricas [A]  time = 0.42, size = 175, normalized size = 1.52 \begin {gather*} \left [\frac {15 \, \sqrt {a} b^{3} x^{4} \log \left (\frac {b x^{2} + 2 \, a x + 2 \, \sqrt {b x^{3} + a x^{2}} \sqrt {a}}{x^{2}}\right ) - 2 \, {\left (15 \, a b^{2} x^{2} - 10 \, a^{2} b x + 8 \, a^{3}\right )} \sqrt {b x^{3} + a x^{2}}}{48 \, a^{4} x^{4}}, -\frac {15 \, \sqrt {-a} b^{3} x^{4} \arctan \left (\frac {\sqrt {b x^{3} + a x^{2}} \sqrt {-a}}{a x}\right ) + {\left (15 \, a b^{2} x^{2} - 10 \, a^{2} b x + 8 \, a^{3}\right )} \sqrt {b x^{3} + a x^{2}}}{24 \, a^{4} x^{4}}\right ] \end {gather*}

Verification of antiderivative is not currently implemented for this CAS.

[In]

integrate(1/x^3/(b*x^3+a*x^2)^(1/2),x, algorithm="fricas")

[Out]

[1/48*(15*sqrt(a)*b^3*x^4*log((b*x^2 + 2*a*x + 2*sqrt(b*x^3 + a*x^2)*sqrt(a))/x^2) - 2*(15*a*b^2*x^2 - 10*a^2*
b*x + 8*a^3)*sqrt(b*x^3 + a*x^2))/(a^4*x^4), -1/24*(15*sqrt(-a)*b^3*x^4*arctan(sqrt(b*x^3 + a*x^2)*sqrt(-a)/(a
*x)) + (15*a*b^2*x^2 - 10*a^2*b*x + 8*a^3)*sqrt(b*x^3 + a*x^2))/(a^4*x^4)]

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giac [F(-2)]  time = 0.00, size = 0, normalized size = 0.00 \begin {gather*} \text {Exception raised: NotImplementedError} \end {gather*}

Verification of antiderivative is not currently implemented for this CAS.

[In]

integrate(1/x^3/(b*x^3+a*x^2)^(1/2),x, algorithm="giac")

[Out]

Exception raised: NotImplementedError >> Unable to parse Giac output: Warning, choosing root of [1,0,%%%{-4,[1
,0,0]%%%}+%%%{-2,[0,1,1]%%%},0,%%%{1,[0,2,2]%%%}] at parameters values [62.4600259969,-13,46]2*((-16*a^2/96/a^
3/x+20*a*b/96/a^3)/x-30*b^2/96/a^3)*sqrt(a*(1/x)^2+b/x)-10*b^3/32/a^3/sqrt(a)*ln(abs(2*sqrt(a)*(sqrt(a*(1/x)^2
+b/x)-sqrt(a)/x)-b))

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maple [A]  time = 0.06, size = 95, normalized size = 0.83 \begin {gather*} -\frac {\sqrt {b x +a}\, \left (-15 a \,b^{3} x^{3} \arctanh \left (\frac {\sqrt {b x +a}}{\sqrt {a}}\right )+15 \sqrt {b x +a}\, a^{\frac {3}{2}} b^{2} x^{2}-10 \sqrt {b x +a}\, a^{\frac {5}{2}} b x +8 \sqrt {b x +a}\, a^{\frac {7}{2}}\right )}{24 \sqrt {b \,x^{3}+a \,x^{2}}\, a^{\frac {9}{2}} x^{2}} \end {gather*}

Verification of antiderivative is not currently implemented for this CAS.

[In]

int(1/x^3/(b*x^3+a*x^2)^(1/2),x)

[Out]

-1/24/x^2*(b*x+a)^(1/2)*(15*(b*x+a)^(1/2)*a^(3/2)*x^2*b^2-15*arctanh((b*x+a)^(1/2)/a^(1/2))*x^3*a*b^3-10*(b*x+
a)^(1/2)*a^(5/2)*x*b+8*(b*x+a)^(1/2)*a^(7/2))/(b*x^3+a*x^2)^(1/2)/a^(9/2)

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maxima [F]  time = 0.00, size = 0, normalized size = 0.00 \begin {gather*} \int \frac {1}{\sqrt {b x^{3} + a x^{2}} x^{3}}\,{d x} \end {gather*}

Verification of antiderivative is not currently implemented for this CAS.

[In]

integrate(1/x^3/(b*x^3+a*x^2)^(1/2),x, algorithm="maxima")

[Out]

integrate(1/(sqrt(b*x^3 + a*x^2)*x^3), x)

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mupad [F]  time = 0.00, size = -1, normalized size = -0.01 \begin {gather*} \int \frac {1}{x^3\,\sqrt {b\,x^3+a\,x^2}} \,d x \end {gather*}

Verification of antiderivative is not currently implemented for this CAS.

[In]

int(1/(x^3*(a*x^2 + b*x^3)^(1/2)),x)

[Out]

int(1/(x^3*(a*x^2 + b*x^3)^(1/2)), x)

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sympy [F]  time = 0.00, size = 0, normalized size = 0.00 \begin {gather*} \int \frac {1}{x^{3} \sqrt {x^{2} \left (a + b x\right )}}\, dx \end {gather*}

Verification of antiderivative is not currently implemented for this CAS.

[In]

integrate(1/x**3/(b*x**3+a*x**2)**(1/2),x)

[Out]

Integral(1/(x**3*sqrt(x**2*(a + b*x))), x)

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