3.2057 \(\int \frac{1}{a+\frac{b}{x^4}} \, dx\)

Optimal. Leaf size=190 \[ \frac{\sqrt [4]{b} \log \left (-\sqrt{2} \sqrt [4]{a} \sqrt [4]{b} x+\sqrt{a} x^2+\sqrt{b}\right )}{4 \sqrt{2} a^{5/4}}-\frac{\sqrt [4]{b} \log \left (\sqrt{2} \sqrt [4]{a} \sqrt [4]{b} x+\sqrt{a} x^2+\sqrt{b}\right )}{4 \sqrt{2} a^{5/4}}+\frac{\sqrt [4]{b} \tan ^{-1}\left (1-\frac{\sqrt{2} \sqrt [4]{a} x}{\sqrt [4]{b}}\right )}{2 \sqrt{2} a^{5/4}}-\frac{\sqrt [4]{b} \tan ^{-1}\left (\frac{\sqrt{2} \sqrt [4]{a} x}{\sqrt [4]{b}}+1\right )}{2 \sqrt{2} a^{5/4}}+\frac{x}{a} \]

[Out]

x/a + (b^(1/4)*ArcTan[1 - (Sqrt[2]*a^(1/4)*x)/b^(1/4)])/(2*Sqrt[2]*a^(5/4)) - (b^(1/4)*ArcTan[1 + (Sqrt[2]*a^(
1/4)*x)/b^(1/4)])/(2*Sqrt[2]*a^(5/4)) + (b^(1/4)*Log[Sqrt[b] - Sqrt[2]*a^(1/4)*b^(1/4)*x + Sqrt[a]*x^2])/(4*Sq
rt[2]*a^(5/4)) - (b^(1/4)*Log[Sqrt[b] + Sqrt[2]*a^(1/4)*b^(1/4)*x + Sqrt[a]*x^2])/(4*Sqrt[2]*a^(5/4))

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Rubi [A]  time = 0.132312, antiderivative size = 190, normalized size of antiderivative = 1., number of steps used = 11, number of rules used = 8, integrand size = 9, \(\frac{\text{number of rules}}{\text{integrand size}}\) = 0.889, Rules used = {193, 321, 211, 1165, 628, 1162, 617, 204} \[ \frac{\sqrt [4]{b} \log \left (-\sqrt{2} \sqrt [4]{a} \sqrt [4]{b} x+\sqrt{a} x^2+\sqrt{b}\right )}{4 \sqrt{2} a^{5/4}}-\frac{\sqrt [4]{b} \log \left (\sqrt{2} \sqrt [4]{a} \sqrt [4]{b} x+\sqrt{a} x^2+\sqrt{b}\right )}{4 \sqrt{2} a^{5/4}}+\frac{\sqrt [4]{b} \tan ^{-1}\left (1-\frac{\sqrt{2} \sqrt [4]{a} x}{\sqrt [4]{b}}\right )}{2 \sqrt{2} a^{5/4}}-\frac{\sqrt [4]{b} \tan ^{-1}\left (\frac{\sqrt{2} \sqrt [4]{a} x}{\sqrt [4]{b}}+1\right )}{2 \sqrt{2} a^{5/4}}+\frac{x}{a} \]

Antiderivative was successfully verified.

[In]

Int[(a + b/x^4)^(-1),x]

[Out]

x/a + (b^(1/4)*ArcTan[1 - (Sqrt[2]*a^(1/4)*x)/b^(1/4)])/(2*Sqrt[2]*a^(5/4)) - (b^(1/4)*ArcTan[1 + (Sqrt[2]*a^(
1/4)*x)/b^(1/4)])/(2*Sqrt[2]*a^(5/4)) + (b^(1/4)*Log[Sqrt[b] - Sqrt[2]*a^(1/4)*b^(1/4)*x + Sqrt[a]*x^2])/(4*Sq
rt[2]*a^(5/4)) - (b^(1/4)*Log[Sqrt[b] + Sqrt[2]*a^(1/4)*b^(1/4)*x + Sqrt[a]*x^2])/(4*Sqrt[2]*a^(5/4))

Rule 193

Int[((a_) + (b_.)*(x_)^(n_))^(p_), x_Symbol] :> Int[x^(n*p)*(b + a/x^n)^p, x] /; FreeQ[{a, b}, x] && LtQ[n, 0]
&& IntegerQ[p]

Rule 321

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

Rule 211

Int[((a_) + (b_.)*(x_)^4)^(-1), x_Symbol] :> With[{r = Numerator[Rt[a/b, 2]], s = Denominator[Rt[a/b, 2]]}, Di
st[1/(2*r), Int[(r - s*x^2)/(a + b*x^4), x], x] + Dist[1/(2*r), Int[(r + s*x^2)/(a + b*x^4), x], x]] /; FreeQ[
{a, b}, x] && (GtQ[a/b, 0] || (PosQ[a/b] && AtomQ[SplitProduct[SumBaseQ, a]] && AtomQ[SplitProduct[SumBaseQ, b
]]))

Rule 1165

Int[((d_) + (e_.)*(x_)^2)/((a_) + (c_.)*(x_)^4), x_Symbol] :> With[{q = Rt[(-2*d)/e, 2]}, Dist[e/(2*c*q), Int[
(q - 2*x)/Simp[d/e + q*x - x^2, x], x], x] + Dist[e/(2*c*q), Int[(q + 2*x)/Simp[d/e - q*x - x^2, x], x], x]] /
; FreeQ[{a, c, d, e}, x] && EqQ[c*d^2 - a*e^2, 0] && NegQ[d*e]

Rule 628

Int[((d_) + (e_.)*(x_))/((a_.) + (b_.)*(x_) + (c_.)*(x_)^2), x_Symbol] :> Simp[(d*Log[RemoveContent[a + b*x +
c*x^2, x]])/b, x] /; FreeQ[{a, b, c, d, e}, x] && EqQ[2*c*d - b*e, 0]

Rule 1162

Int[((d_) + (e_.)*(x_)^2)/((a_) + (c_.)*(x_)^4), x_Symbol] :> With[{q = Rt[(2*d)/e, 2]}, Dist[e/(2*c), Int[1/S
imp[d/e + q*x + x^2, x], x], x] + Dist[e/(2*c), Int[1/Simp[d/e - q*x + x^2, x], x], x]] /; FreeQ[{a, c, d, e},
x] && EqQ[c*d^2 - a*e^2, 0] && PosQ[d*e]

Rule 617

Int[((a_) + (b_.)*(x_) + (c_.)*(x_)^2)^(-1), x_Symbol] :> With[{q = 1 - 4*Simplify[(a*c)/b^2]}, Dist[-2/b, Sub
st[Int[1/(q - x^2), x], x, 1 + (2*c*x)/b], x] /; RationalQ[q] && (EqQ[q^2, 1] ||  !RationalQ[b^2 - 4*a*c])] /;
FreeQ[{a, b, c}, x] && NeQ[b^2 - 4*a*c, 0]

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}{a+\frac{b}{x^4}} \, dx &=\int \frac{x^4}{b+a x^4} \, dx\\ &=\frac{x}{a}-\frac{b \int \frac{1}{b+a x^4} \, dx}{a}\\ &=\frac{x}{a}-\frac{\sqrt{b} \int \frac{\sqrt{b}-\sqrt{a} x^2}{b+a x^4} \, dx}{2 a}-\frac{\sqrt{b} \int \frac{\sqrt{b}+\sqrt{a} x^2}{b+a x^4} \, dx}{2 a}\\ &=\frac{x}{a}+\frac{\sqrt [4]{b} \int \frac{\frac{\sqrt{2} \sqrt [4]{b}}{\sqrt [4]{a}}+2 x}{-\frac{\sqrt{b}}{\sqrt{a}}-\frac{\sqrt{2} \sqrt [4]{b} x}{\sqrt [4]{a}}-x^2} \, dx}{4 \sqrt{2} a^{5/4}}+\frac{\sqrt [4]{b} \int \frac{\frac{\sqrt{2} \sqrt [4]{b}}{\sqrt [4]{a}}-2 x}{-\frac{\sqrt{b}}{\sqrt{a}}+\frac{\sqrt{2} \sqrt [4]{b} x}{\sqrt [4]{a}}-x^2} \, dx}{4 \sqrt{2} a^{5/4}}-\frac{\sqrt{b} \int \frac{1}{\frac{\sqrt{b}}{\sqrt{a}}-\frac{\sqrt{2} \sqrt [4]{b} x}{\sqrt [4]{a}}+x^2} \, dx}{4 a^{3/2}}-\frac{\sqrt{b} \int \frac{1}{\frac{\sqrt{b}}{\sqrt{a}}+\frac{\sqrt{2} \sqrt [4]{b} x}{\sqrt [4]{a}}+x^2} \, dx}{4 a^{3/2}}\\ &=\frac{x}{a}+\frac{\sqrt [4]{b} \log \left (\sqrt{b}-\sqrt{2} \sqrt [4]{a} \sqrt [4]{b} x+\sqrt{a} x^2\right )}{4 \sqrt{2} a^{5/4}}-\frac{\sqrt [4]{b} \log \left (\sqrt{b}+\sqrt{2} \sqrt [4]{a} \sqrt [4]{b} x+\sqrt{a} x^2\right )}{4 \sqrt{2} a^{5/4}}-\frac{\sqrt [4]{b} \operatorname{Subst}\left (\int \frac{1}{-1-x^2} \, dx,x,1-\frac{\sqrt{2} \sqrt [4]{a} x}{\sqrt [4]{b}}\right )}{2 \sqrt{2} a^{5/4}}+\frac{\sqrt [4]{b} \operatorname{Subst}\left (\int \frac{1}{-1-x^2} \, dx,x,1+\frac{\sqrt{2} \sqrt [4]{a} x}{\sqrt [4]{b}}\right )}{2 \sqrt{2} a^{5/4}}\\ &=\frac{x}{a}+\frac{\sqrt [4]{b} \tan ^{-1}\left (1-\frac{\sqrt{2} \sqrt [4]{a} x}{\sqrt [4]{b}}\right )}{2 \sqrt{2} a^{5/4}}-\frac{\sqrt [4]{b} \tan ^{-1}\left (1+\frac{\sqrt{2} \sqrt [4]{a} x}{\sqrt [4]{b}}\right )}{2 \sqrt{2} a^{5/4}}+\frac{\sqrt [4]{b} \log \left (\sqrt{b}-\sqrt{2} \sqrt [4]{a} \sqrt [4]{b} x+\sqrt{a} x^2\right )}{4 \sqrt{2} a^{5/4}}-\frac{\sqrt [4]{b} \log \left (\sqrt{b}+\sqrt{2} \sqrt [4]{a} \sqrt [4]{b} x+\sqrt{a} x^2\right )}{4 \sqrt{2} a^{5/4}}\\ \end{align*}

Mathematica [A]  time = 0.0489001, size = 173, normalized size = 0.91 \[ \frac{\sqrt{2} \sqrt [4]{b} \log \left (-\sqrt{2} \sqrt [4]{a} \sqrt [4]{b} x+\sqrt{a} x^2+\sqrt{b}\right )-\sqrt{2} \sqrt [4]{b} \log \left (\sqrt{2} \sqrt [4]{a} \sqrt [4]{b} x+\sqrt{a} x^2+\sqrt{b}\right )+2 \sqrt{2} \sqrt [4]{b} \tan ^{-1}\left (1-\frac{\sqrt{2} \sqrt [4]{a} x}{\sqrt [4]{b}}\right )-2 \sqrt{2} \sqrt [4]{b} \tan ^{-1}\left (\frac{\sqrt{2} \sqrt [4]{a} x}{\sqrt [4]{b}}+1\right )+8 \sqrt [4]{a} x}{8 a^{5/4}} \]

Antiderivative was successfully verified.

[In]

Integrate[(a + b/x^4)^(-1),x]

[Out]

(8*a^(1/4)*x + 2*Sqrt[2]*b^(1/4)*ArcTan[1 - (Sqrt[2]*a^(1/4)*x)/b^(1/4)] - 2*Sqrt[2]*b^(1/4)*ArcTan[1 + (Sqrt[
2]*a^(1/4)*x)/b^(1/4)] + Sqrt[2]*b^(1/4)*Log[Sqrt[b] - Sqrt[2]*a^(1/4)*b^(1/4)*x + Sqrt[a]*x^2] - Sqrt[2]*b^(1
/4)*Log[Sqrt[b] + Sqrt[2]*a^(1/4)*b^(1/4)*x + Sqrt[a]*x^2])/(8*a^(5/4))

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Maple [A]  time = 0.007, size = 133, normalized size = 0.7 \begin{align*}{\frac{x}{a}}-{\frac{\sqrt{2}}{8\,a}\sqrt [4]{{\frac{b}{a}}}\ln \left ({ \left ({x}^{2}+\sqrt [4]{{\frac{b}{a}}}x\sqrt{2}+\sqrt{{\frac{b}{a}}} \right ) \left ({x}^{2}-\sqrt [4]{{\frac{b}{a}}}x\sqrt{2}+\sqrt{{\frac{b}{a}}} \right ) ^{-1}} \right ) }-{\frac{\sqrt{2}}{4\,a}\sqrt [4]{{\frac{b}{a}}}\arctan \left ({x\sqrt{2}{\frac{1}{\sqrt [4]{{\frac{b}{a}}}}}}+1 \right ) }-{\frac{\sqrt{2}}{4\,a}\sqrt [4]{{\frac{b}{a}}}\arctan \left ({x\sqrt{2}{\frac{1}{\sqrt [4]{{\frac{b}{a}}}}}}-1 \right ) } \end{align*}

Verification of antiderivative is not currently implemented for this CAS.

[In]

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

[Out]

x/a-1/8/a*(b/a)^(1/4)*2^(1/2)*ln((x^2+(b/a)^(1/4)*x*2^(1/2)+(b/a)^(1/2))/(x^2-(b/a)^(1/4)*x*2^(1/2)+(b/a)^(1/2
)))-1/4/a*(b/a)^(1/4)*2^(1/2)*arctan(2^(1/2)/(b/a)^(1/4)*x+1)-1/4/a*(b/a)^(1/4)*2^(1/2)*arctan(2^(1/2)/(b/a)^(
1/4)*x-1)

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Maxima [F(-2)]  time = 0., size = 0, normalized size = 0. \begin{align*} \text{Exception raised: ValueError} \end{align*}

Verification of antiderivative is not currently implemented for this CAS.

[In]

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

[Out]

Exception raised: ValueError

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Fricas [A]  time = 1.84611, size = 284, normalized size = 1.49 \begin{align*} -\frac{4 \, a \left (-\frac{b}{a^{5}}\right )^{\frac{1}{4}} \arctan \left (-\frac{a^{4} x \left (-\frac{b}{a^{5}}\right )^{\frac{3}{4}} - \sqrt{a^{2} \sqrt{-\frac{b}{a^{5}}} + x^{2}} a^{4} \left (-\frac{b}{a^{5}}\right )^{\frac{3}{4}}}{b}\right ) + a \left (-\frac{b}{a^{5}}\right )^{\frac{1}{4}} \log \left (a \left (-\frac{b}{a^{5}}\right )^{\frac{1}{4}} + x\right ) - a \left (-\frac{b}{a^{5}}\right )^{\frac{1}{4}} \log \left (-a \left (-\frac{b}{a^{5}}\right )^{\frac{1}{4}} + x\right ) - 4 \, x}{4 \, a} \end{align*}

Verification of antiderivative is not currently implemented for this CAS.

[In]

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

[Out]

-1/4*(4*a*(-b/a^5)^(1/4)*arctan(-(a^4*x*(-b/a^5)^(3/4) - sqrt(a^2*sqrt(-b/a^5) + x^2)*a^4*(-b/a^5)^(3/4))/b) +
a*(-b/a^5)^(1/4)*log(a*(-b/a^5)^(1/4) + x) - a*(-b/a^5)^(1/4)*log(-a*(-b/a^5)^(1/4) + x) - 4*x)/a

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Sympy [A]  time = 0.313245, size = 22, normalized size = 0.12 \begin{align*} \operatorname{RootSum}{\left (256 t^{4} a^{5} + b, \left ( t \mapsto t \log{\left (- 4 t a + x \right )} \right )\right )} + \frac{x}{a} \end{align*}

Verification of antiderivative is not currently implemented for this CAS.

[In]

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

[Out]

RootSum(256*_t**4*a**5 + b, Lambda(_t, _t*log(-4*_t*a + x))) + x/a

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Giac [A]  time = 1.09517, size = 232, normalized size = 1.22 \begin{align*} \frac{x}{a} - \frac{\sqrt{2} \left (a^{3} b\right )^{\frac{1}{4}} \arctan \left (\frac{\sqrt{2}{\left (2 \, x + \sqrt{2} \left (\frac{b}{a}\right )^{\frac{1}{4}}\right )}}{2 \, \left (\frac{b}{a}\right )^{\frac{1}{4}}}\right )}{4 \, a^{2}} - \frac{\sqrt{2} \left (a^{3} b\right )^{\frac{1}{4}} \arctan \left (\frac{\sqrt{2}{\left (2 \, x - \sqrt{2} \left (\frac{b}{a}\right )^{\frac{1}{4}}\right )}}{2 \, \left (\frac{b}{a}\right )^{\frac{1}{4}}}\right )}{4 \, a^{2}} - \frac{\sqrt{2} \left (a^{3} b\right )^{\frac{1}{4}} \log \left (x^{2} + \sqrt{2} x \left (\frac{b}{a}\right )^{\frac{1}{4}} + \sqrt{\frac{b}{a}}\right )}{8 \, a^{2}} + \frac{\sqrt{2} \left (a^{3} b\right )^{\frac{1}{4}} \log \left (x^{2} - \sqrt{2} x \left (\frac{b}{a}\right )^{\frac{1}{4}} + \sqrt{\frac{b}{a}}\right )}{8 \, a^{2}} \end{align*}

Verification of antiderivative is not currently implemented for this CAS.

[In]

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

[Out]

x/a - 1/4*sqrt(2)*(a^3*b)^(1/4)*arctan(1/2*sqrt(2)*(2*x + sqrt(2)*(b/a)^(1/4))/(b/a)^(1/4))/a^2 - 1/4*sqrt(2)*
(a^3*b)^(1/4)*arctan(1/2*sqrt(2)*(2*x - sqrt(2)*(b/a)^(1/4))/(b/a)^(1/4))/a^2 - 1/8*sqrt(2)*(a^3*b)^(1/4)*log(
x^2 + sqrt(2)*x*(b/a)^(1/4) + sqrt(b/a))/a^2 + 1/8*sqrt(2)*(a^3*b)^(1/4)*log(x^2 - sqrt(2)*x*(b/a)^(1/4) + sqr
t(b/a))/a^2