3.2506 \(\int \frac {1}{x^3 \sqrt {a+b x^n}} \, dx\)

Optimal. Leaf size=51 \[ -\frac {\sqrt {a+b x^n} \, _2F_1\left (1,\frac {1}{2}-\frac {2}{n};-\frac {2-n}{n};-\frac {b x^n}{a}\right )}{2 a x^2} \]

[Out]

-1/2*hypergeom([1, 1/2-2/n],[(-2+n)/n],-b*x^n/a)*(a+b*x^n)^(1/2)/a/x^2

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Rubi [A]  time = 0.02, antiderivative size = 60, normalized size of antiderivative = 1.18, number of steps used = 2, number of rules used = 2, integrand size = 15, \(\frac {\text {number of rules}}{\text {integrand size}}\) = 0.133, Rules used = {365, 364} \[ -\frac {\sqrt {\frac {b x^n}{a}+1} \, _2F_1\left (\frac {1}{2},-\frac {2}{n};-\frac {2-n}{n};-\frac {b x^n}{a}\right )}{2 x^2 \sqrt {a+b x^n}} \]

Antiderivative was successfully verified.

[In]

Int[1/(x^3*Sqrt[a + b*x^n]),x]

[Out]

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

Rule 364

Int[((c_.)*(x_))^(m_.)*((a_) + (b_.)*(x_)^(n_))^(p_), x_Symbol] :> Simp[(a^p*(c*x)^(m + 1)*Hypergeometric2F1[-
p, (m + 1)/n, (m + 1)/n + 1, -((b*x^n)/a)])/(c*(m + 1)), x] /; FreeQ[{a, b, c, m, n, p}, x] &&  !IGtQ[p, 0] &&
(ILtQ[p, 0] || GtQ[a, 0])

Rule 365

Int[((c_.)*(x_))^(m_.)*((a_) + (b_.)*(x_)^(n_))^(p_), x_Symbol] :> Dist[(a^IntPart[p]*(a + b*x^n)^FracPart[p])
/(1 + (b*x^n)/a)^FracPart[p], Int[(c*x)^m*(1 + (b*x^n)/a)^p, x], x] /; FreeQ[{a, b, c, m, n, p}, x] &&  !IGtQ[
p, 0] &&  !(ILtQ[p, 0] || GtQ[a, 0])

Rubi steps

\begin {align*} \int \frac {1}{x^3 \sqrt {a+b x^n}} \, dx &=\frac {\sqrt {1+\frac {b x^n}{a}} \int \frac {1}{x^3 \sqrt {1+\frac {b x^n}{a}}} \, dx}{\sqrt {a+b x^n}}\\ &=-\frac {\sqrt {1+\frac {b x^n}{a}} \, _2F_1\left (\frac {1}{2},-\frac {2}{n};-\frac {2-n}{n};-\frac {b x^n}{a}\right )}{2 x^2 \sqrt {a+b x^n}}\\ \end {align*}

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Mathematica [A]  time = 0.02, size = 57, normalized size = 1.12 \[ -\frac {\sqrt {\frac {b x^n}{a}+1} \, _2F_1\left (\frac {1}{2},-\frac {2}{n};1-\frac {2}{n};-\frac {b x^n}{a}\right )}{2 x^2 \sqrt {a+b x^n}} \]

Antiderivative was successfully verified.

[In]

Integrate[1/(x^3*Sqrt[a + b*x^n]),x]

[Out]

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

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fricas [F(-2)]  time = 0.00, size = 0, normalized size = 0.00 \[ \text {Exception raised: TypeError} \]

Verification of antiderivative is not currently implemented for this CAS.

[In]

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

[Out]

Exception raised: TypeError >>  Error detected within library code:   integrate: implementation incomplete (co
nstant residues)

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giac [F]  time = 0.00, size = 0, normalized size = 0.00 \[ \int \frac {1}{\sqrt {b x^{n} + a} x^{3}}\,{d x} \]

Verification of antiderivative is not currently implemented for this CAS.

[In]

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

[Out]

integrate(1/(sqrt(b*x^n + a)*x^3), x)

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maple [F]  time = 0.20, size = 0, normalized size = 0.00 \[ \int \frac {1}{\sqrt {b \,x^{n}+a}\, x^{3}}\, dx \]

Verification of antiderivative is not currently implemented for this CAS.

[In]

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

[Out]

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

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

Verification of antiderivative is not currently implemented for this CAS.

[In]

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

[Out]

integrate(1/(sqrt(b*x^n + a)*x^3), x)

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mupad [F]  time = 0.00, size = -1, normalized size = -0.02 \[ \int \frac {1}{x^3\,\sqrt {a+b\,x^n}} \,d x \]

Verification of antiderivative is not currently implemented for this CAS.

[In]

int(1/(x^3*(a + b*x^n)^(1/2)),x)

[Out]

int(1/(x^3*(a + b*x^n)^(1/2)), x)

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sympy [C]  time = 1.58, size = 44, normalized size = 0.86 \[ \frac {\Gamma \left (- \frac {2}{n}\right ) {{}_{2}F_{1}\left (\begin {matrix} \frac {1}{2}, - \frac {2}{n} \\ 1 - \frac {2}{n} \end {matrix}\middle | {\frac {b x^{n} e^{i \pi }}{a}} \right )}}{\sqrt {a} n x^{2} \Gamma \left (1 - \frac {2}{n}\right )} \]

Verification of antiderivative is not currently implemented for this CAS.

[In]

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

[Out]

gamma(-2/n)*hyper((1/2, -2/n), (1 - 2/n,), b*x**n*exp_polar(I*pi)/a)/(sqrt(a)*n*x**2*gamma(1 - 2/n))

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