3.1185 \(\int x \sqrt [4]{a-b x^4} \, dx\)

Optimal. Leaf size=82 \[ \frac{a^{3/2} \left (1-\frac{b x^4}{a}\right )^{3/4} \text{EllipticF}\left (\frac{1}{2} \sin ^{-1}\left (\frac{\sqrt{b} x^2}{\sqrt{a}}\right ),2\right )}{3 \sqrt{b} \left (a-b x^4\right )^{3/4}}+\frac{1}{3} x^2 \sqrt [4]{a-b x^4} \]

[Out]

(x^2*(a - b*x^4)^(1/4))/3 + (a^(3/2)*(1 - (b*x^4)/a)^(3/4)*EllipticF[ArcSin[(Sqrt[b]*x^2)/Sqrt[a]]/2, 2])/(3*S
qrt[b]*(a - b*x^4)^(3/4))

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Rubi [A]  time = 0.0427203, antiderivative size = 82, normalized size of antiderivative = 1., number of steps used = 4, number of rules used = 4, integrand size = 14, \(\frac{\text{number of rules}}{\text{integrand size}}\) = 0.286, Rules used = {275, 195, 233, 232} \[ \frac{a^{3/2} \left (1-\frac{b x^4}{a}\right )^{3/4} F\left (\left .\frac{1}{2} \sin ^{-1}\left (\frac{\sqrt{b} x^2}{\sqrt{a}}\right )\right |2\right )}{3 \sqrt{b} \left (a-b x^4\right )^{3/4}}+\frac{1}{3} x^2 \sqrt [4]{a-b x^4} \]

Antiderivative was successfully verified.

[In]

Int[x*(a - b*x^4)^(1/4),x]

[Out]

(x^2*(a - b*x^4)^(1/4))/3 + (a^(3/2)*(1 - (b*x^4)/a)^(3/4)*EllipticF[ArcSin[(Sqrt[b]*x^2)/Sqrt[a]]/2, 2])/(3*S
qrt[b]*(a - b*x^4)^(3/4))

Rule 275

Int[(x_)^(m_.)*((a_) + (b_.)*(x_)^(n_))^(p_), x_Symbol] :> With[{k = GCD[m + 1, n]}, Dist[1/k, Subst[Int[x^((m
+ 1)/k - 1)*(a + b*x^(n/k))^p, x], x, x^k], x] /; k != 1] /; FreeQ[{a, b, p}, x] && IGtQ[n, 0] && IntegerQ[m]

Rule 195

Int[((a_) + (b_.)*(x_)^(n_))^(p_), x_Symbol] :> Simp[(x*(a + b*x^n)^p)/(n*p + 1), x] + Dist[(a*n*p)/(n*p + 1),
Int[(a + b*x^n)^(p - 1), x], x] /; FreeQ[{a, b}, x] && IGtQ[n, 0] && GtQ[p, 0] && (IntegerQ[2*p] || (EqQ[n, 2
] && IntegerQ[4*p]) || (EqQ[n, 2] && IntegerQ[3*p]) || LtQ[Denominator[p + 1/n], Denominator[p]])

Rule 233

Int[((a_) + (b_.)*(x_)^2)^(-3/4), x_Symbol] :> Dist[(1 + (b*x^2)/a)^(3/4)/(a + b*x^2)^(3/4), Int[1/(1 + (b*x^2
)/a)^(3/4), x], x] /; FreeQ[{a, b}, x] && PosQ[a]

Rule 232

Int[((a_) + (b_.)*(x_)^2)^(-3/4), x_Symbol] :> Simp[(2*EllipticF[(1*ArcSin[Rt[-(b/a), 2]*x])/2, 2])/(a^(3/4)*R
t[-(b/a), 2]), x] /; FreeQ[{a, b}, x] && GtQ[a, 0] && NegQ[b/a]

Rubi steps

\begin{align*} \int x \sqrt [4]{a-b x^4} \, dx &=\frac{1}{2} \operatorname{Subst}\left (\int \sqrt [4]{a-b x^2} \, dx,x,x^2\right )\\ &=\frac{1}{3} x^2 \sqrt [4]{a-b x^4}+\frac{1}{6} a \operatorname{Subst}\left (\int \frac{1}{\left (a-b x^2\right )^{3/4}} \, dx,x,x^2\right )\\ &=\frac{1}{3} x^2 \sqrt [4]{a-b x^4}+\frac{\left (a \left (1-\frac{b x^4}{a}\right )^{3/4}\right ) \operatorname{Subst}\left (\int \frac{1}{\left (1-\frac{b x^2}{a}\right )^{3/4}} \, dx,x,x^2\right )}{6 \left (a-b x^4\right )^{3/4}}\\ &=\frac{1}{3} x^2 \sqrt [4]{a-b x^4}+\frac{a^{3/2} \left (1-\frac{b x^4}{a}\right )^{3/4} F\left (\left .\frac{1}{2} \sin ^{-1}\left (\frac{\sqrt{b} x^2}{\sqrt{a}}\right )\right |2\right )}{3 \sqrt{b} \left (a-b x^4\right )^{3/4}}\\ \end{align*}

Mathematica [C]  time = 0.0103342, size = 52, normalized size = 0.63 \[ \frac{x^2 \sqrt [4]{a-b x^4} \, _2F_1\left (-\frac{1}{4},\frac{1}{2};\frac{3}{2};\frac{b x^4}{a}\right )}{2 \sqrt [4]{1-\frac{b x^4}{a}}} \]

Antiderivative was successfully verified.

[In]

Integrate[x*(a - b*x^4)^(1/4),x]

[Out]

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

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Maple [F]  time = 0.013, size = 0, normalized size = 0. \begin{align*} \int x\sqrt [4]{-b{x}^{4}+a}\, dx \end{align*}

Verification of antiderivative is not currently implemented for this CAS.

[In]

int(x*(-b*x^4+a)^(1/4),x)

[Out]

int(x*(-b*x^4+a)^(1/4),x)

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Maxima [F]  time = 0., size = 0, normalized size = 0. \begin{align*} \int{\left (-b x^{4} + a\right )}^{\frac{1}{4}} x\,{d x} \end{align*}

Verification of antiderivative is not currently implemented for this CAS.

[In]

integrate(x*(-b*x^4+a)^(1/4),x, algorithm="maxima")

[Out]

integrate((-b*x^4 + a)^(1/4)*x, x)

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Fricas [F]  time = 0., size = 0, normalized size = 0. \begin{align*}{\rm integral}\left ({\left (-b x^{4} + a\right )}^{\frac{1}{4}} x, x\right ) \end{align*}

Verification of antiderivative is not currently implemented for this CAS.

[In]

integrate(x*(-b*x^4+a)^(1/4),x, algorithm="fricas")

[Out]

integral((-b*x^4 + a)^(1/4)*x, x)

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Sympy [C]  time = 0.961479, size = 31, normalized size = 0.38 \begin{align*} \frac{\sqrt [4]{a} x^{2}{{}_{2}F_{1}\left (\begin{matrix} - \frac{1}{4}, \frac{1}{2} \\ \frac{3}{2} \end{matrix}\middle |{\frac{b x^{4} e^{2 i \pi }}{a}} \right )}}{2} \end{align*}

Verification of antiderivative is not currently implemented for this CAS.

[In]

integrate(x*(-b*x**4+a)**(1/4),x)

[Out]

a**(1/4)*x**2*hyper((-1/4, 1/2), (3/2,), b*x**4*exp_polar(2*I*pi)/a)/2

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Giac [F]  time = 0., size = 0, normalized size = 0. \begin{align*} \int{\left (-b x^{4} + a\right )}^{\frac{1}{4}} x\,{d x} \end{align*}

Verification of antiderivative is not currently implemented for this CAS.

[In]

integrate(x*(-b*x^4+a)^(1/4),x, algorithm="giac")

[Out]

integrate((-b*x^4 + a)^(1/4)*x, x)