3.2599 \(\int \frac {x^{-1+3 n}}{a+b x^n} \, dx\)

Optimal. Leaf size=46 \[ \frac {a^2 \log \left (a+b x^n\right )}{b^3 n}-\frac {a x^n}{b^2 n}+\frac {x^{2 n}}{2 b n} \]

[Out]

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

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Rubi [A]  time = 0.03, antiderivative size = 46, normalized size of antiderivative = 1.00, number of steps used = 3, number of rules used = 2, integrand size = 17, \(\frac {\text {number of rules}}{\text {integrand size}}\) = 0.118, Rules used = {266, 43} \[ \frac {a^2 \log \left (a+b x^n\right )}{b^3 n}-\frac {a x^n}{b^2 n}+\frac {x^{2 n}}{2 b n} \]

Antiderivative was successfully verified.

[In]

Int[x^(-1 + 3*n)/(a + b*x^n),x]

[Out]

-((a*x^n)/(b^2*n)) + x^(2*n)/(2*b*n) + (a^2*Log[a + b*x^n])/(b^3*n)

Rule 43

Int[((a_.) + (b_.)*(x_))^(m_.)*((c_.) + (d_.)*(x_))^(n_.), x_Symbol] :> Int[ExpandIntegrand[(a + b*x)^m*(c + d
*x)^n, x], x] /; FreeQ[{a, b, c, d, n}, x] && NeQ[b*c - a*d, 0] && IGtQ[m, 0] && ( !IntegerQ[n] || (EqQ[c, 0]
&& LeQ[7*m + 4*n + 4, 0]) || LtQ[9*m + 5*(n + 1), 0] || GtQ[m + n + 2, 0])

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]]

Rubi steps

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

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Mathematica [A]  time = 0.05, size = 38, normalized size = 0.83 \[ \frac {2 a^2 \log \left (a+b x^n\right )+b x^n \left (b x^n-2 a\right )}{2 b^3 n} \]

Antiderivative was successfully verified.

[In]

Integrate[x^(-1 + 3*n)/(a + b*x^n),x]

[Out]

(b*x^n*(-2*a + b*x^n) + 2*a^2*Log[a + b*x^n])/(2*b^3*n)

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fricas [A]  time = 0.83, size = 38, normalized size = 0.83 \[ \frac {b^{2} x^{2 \, n} - 2 \, a b x^{n} + 2 \, a^{2} \log \left (b x^{n} + a\right )}{2 \, b^{3} n} \]

Verification of antiderivative is not currently implemented for this CAS.

[In]

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

[Out]

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

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

Verification of antiderivative is not currently implemented for this CAS.

[In]

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

[Out]

integrate(x^(3*n - 1)/(b*x^n + a), x)

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maple [A]  time = 0.02, size = 51, normalized size = 1.11 \[ \frac {a^{2} \ln \left (b \,{\mathrm e}^{n \ln \relax (x )}+a \right )}{b^{3} n}-\frac {a \,{\mathrm e}^{n \ln \relax (x )}}{b^{2} n}+\frac {{\mathrm e}^{2 n \ln \relax (x )}}{2 b n} \]

Verification of antiderivative is not currently implemented for this CAS.

[In]

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

[Out]

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

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maxima [A]  time = 0.53, size = 45, normalized size = 0.98 \[ \frac {a^{2} \log \left (\frac {b x^{n} + a}{b}\right )}{b^{3} n} + \frac {b x^{2 \, n} - 2 \, a x^{n}}{2 \, b^{2} n} \]

Verification of antiderivative is not currently implemented for this CAS.

[In]

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

[Out]

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

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

Verification of antiderivative is not currently implemented for this CAS.

[In]

int(x^(3*n - 1)/(a + b*x^n),x)

[Out]

int(x^(3*n - 1)/(a + b*x^n), x)

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sympy [A]  time = 25.36, size = 56, normalized size = 1.22 \[ \begin {cases} \frac {\log {\relax (x )}}{a} & \text {for}\: b = 0 \wedge n = 0 \\\frac {\log {\relax (x )}}{a + b} & \text {for}\: n = 0 \\\frac {x^{3 n}}{3 a n} & \text {for}\: b = 0 \\\frac {a^{2} \log {\left (\frac {a}{b} + x^{n} \right )}}{b^{3} n} - \frac {a x^{n}}{b^{2} n} + \frac {x^{2 n}}{2 b n} & \text {otherwise} \end {cases} \]

Verification of antiderivative is not currently implemented for this CAS.

[In]

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

[Out]

Piecewise((log(x)/a, Eq(b, 0) & Eq(n, 0)), (log(x)/(a + b), Eq(n, 0)), (x**(3*n)/(3*a*n), Eq(b, 0)), (a**2*log
(a/b + x**n)/(b**3*n) - a*x**n/(b**2*n) + x**(2*n)/(2*b*n), True))

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