3.496 \(\int \frac{1}{x \sqrt{-1-x^3}} \, dx\)

Optimal. Leaf size=16 \[ \frac{2}{3} \tan ^{-1}\left (\sqrt{-x^3-1}\right ) \]

[Out]

(2*ArcTan[Sqrt[-1 - x^3]])/3

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Rubi [A]  time = 0.0083577, antiderivative size = 16, normalized size of antiderivative = 1., number of steps used = 3, number of rules used = 3, integrand size = 15, \(\frac{\text{number of rules}}{\text{integrand size}}\) = 0.2, Rules used = {266, 63, 204} \[ \frac{2}{3} \tan ^{-1}\left (\sqrt{-x^3-1}\right ) \]

Antiderivative was successfully verified.

[In]

Int[1/(x*Sqrt[-1 - x^3]),x]

[Out]

(2*ArcTan[Sqrt[-1 - x^3]])/3

Rule 266

Int[(x_)^(m_.)*((a_) + (b_.)*(x_)^(n_))^(p_), x_Symbol] :> Dist[1/n, Subst[Int[x^(Simplify[(m + 1)/n] - 1)*(a
+ b*x)^p, x], x, x^n], x] /; FreeQ[{a, b, m, n, p}, x] && IntegerQ[Simplify[(m + 1)/n]]

Rule 63

Int[((a_.) + (b_.)*(x_))^(m_)*((c_.) + (d_.)*(x_))^(n_), x_Symbol] :> With[{p = Denominator[m]}, Dist[p/b, Sub
st[Int[x^(p*(m + 1) - 1)*(c - (a*d)/b + (d*x^p)/b)^n, x], x, (a + b*x)^(1/p)], x]] /; FreeQ[{a, b, c, d}, x] &
& NeQ[b*c - a*d, 0] && LtQ[-1, m, 0] && LeQ[-1, n, 0] && LeQ[Denominator[n], Denominator[m]] && IntLinearQ[a,
b, c, d, m, n, x]

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])

Rubi steps

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

Mathematica [A]  time = 0.0023372, size = 16, normalized size = 1. \[ \frac{2}{3} \tan ^{-1}\left (\sqrt{-x^3-1}\right ) \]

Antiderivative was successfully verified.

[In]

Integrate[1/(x*Sqrt[-1 - x^3]),x]

[Out]

(2*ArcTan[Sqrt[-1 - x^3]])/3

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Maple [A]  time = 0.021, size = 13, normalized size = 0.8 \begin{align*}{\frac{2}{3}\arctan \left ( \sqrt{-{x}^{3}-1} \right ) } \end{align*}

Verification of antiderivative is not currently implemented for this CAS.

[In]

int(1/x/(-x^3-1)^(1/2),x)

[Out]

2/3*arctan((-x^3-1)^(1/2))

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Maxima [A]  time = 1.50993, size = 16, normalized size = 1. \begin{align*} \frac{2}{3} \, \arctan \left (\sqrt{-x^{3} - 1}\right ) \end{align*}

Verification of antiderivative is not currently implemented for this CAS.

[In]

integrate(1/x/(-x^3-1)^(1/2),x, algorithm="maxima")

[Out]

2/3*arctan(sqrt(-x^3 - 1))

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Fricas [A]  time = 1.70377, size = 38, normalized size = 2.38 \begin{align*} \frac{2}{3} \, \arctan \left (\sqrt{-x^{3} - 1}\right ) \end{align*}

Verification of antiderivative is not currently implemented for this CAS.

[In]

integrate(1/x/(-x^3-1)^(1/2),x, algorithm="fricas")

[Out]

2/3*arctan(sqrt(-x^3 - 1))

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Sympy [C]  time = 0.97644, size = 12, normalized size = 0.75 \begin{align*} \frac{2 i \operatorname{asinh}{\left (\frac{1}{x^{\frac{3}{2}}} \right )}}{3} \end{align*}

Verification of antiderivative is not currently implemented for this CAS.

[In]

integrate(1/x/(-x**3-1)**(1/2),x)

[Out]

2*I*asinh(x**(-3/2))/3

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Giac [A]  time = 1.15346, size = 16, normalized size = 1. \begin{align*} \frac{2}{3} \, \arctan \left (\sqrt{-x^{3} - 1}\right ) \end{align*}

Verification of antiderivative is not currently implemented for this CAS.

[In]

integrate(1/x/(-x^3-1)^(1/2),x, algorithm="giac")

[Out]

2/3*arctan(sqrt(-x^3 - 1))