3.2.77 \(\int \frac {x}{\sqrt {a-a \cos (x)}} \, dx\) [177]

Optimal. Leaf size=97 \[ -\frac {4 x \tanh ^{-1}\left (e^{\frac {i x}{2}}\right ) \sin \left (\frac {x}{2}\right )}{\sqrt {a-a \cos (x)}}+\frac {4 i \text {PolyLog}\left (2,-e^{\frac {i x}{2}}\right ) \sin \left (\frac {x}{2}\right )}{\sqrt {a-a \cos (x)}}-\frac {4 i \text {PolyLog}\left (2,e^{\frac {i x}{2}}\right ) \sin \left (\frac {x}{2}\right )}{\sqrt {a-a \cos (x)}} \]

[Out]

-4*x*arctanh(exp(1/2*I*x))*sin(1/2*x)/(a-a*cos(x))^(1/2)+4*I*polylog(2,-exp(1/2*I*x))*sin(1/2*x)/(a-a*cos(x))^
(1/2)-4*I*polylog(2,exp(1/2*I*x))*sin(1/2*x)/(a-a*cos(x))^(1/2)

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Rubi [A]
time = 0.05, antiderivative size = 97, normalized size of antiderivative = 1.00, number of steps used = 6, number of rules used = 4, integrand size = 13, \(\frac {\text {number of rules}}{\text {integrand size}}\) = 0.308, Rules used = {3400, 4268, 2317, 2438} \begin {gather*} \frac {4 i \text {Li}_2\left (-e^{\frac {i x}{2}}\right ) \sin \left (\frac {x}{2}\right )}{\sqrt {a-a \cos (x)}}-\frac {4 i \text {Li}_2\left (e^{\frac {i x}{2}}\right ) \sin \left (\frac {x}{2}\right )}{\sqrt {a-a \cos (x)}}-\frac {4 x \sin \left (\frac {x}{2}\right ) \tanh ^{-1}\left (e^{\frac {i x}{2}}\right )}{\sqrt {a-a \cos (x)}} \end {gather*}

Antiderivative was successfully verified.

[In]

Int[x/Sqrt[a - a*Cos[x]],x]

[Out]

(-4*x*ArcTanh[E^((I/2)*x)]*Sin[x/2])/Sqrt[a - a*Cos[x]] + ((4*I)*PolyLog[2, -E^((I/2)*x)]*Sin[x/2])/Sqrt[a - a
*Cos[x]] - ((4*I)*PolyLog[2, E^((I/2)*x)]*Sin[x/2])/Sqrt[a - a*Cos[x]]

Rule 2317

Int[Log[(a_) + (b_.)*((F_)^((e_.)*((c_.) + (d_.)*(x_))))^(n_.)], x_Symbol] :> Dist[1/(d*e*n*Log[F]), Subst[Int
[Log[a + b*x]/x, x], x, (F^(e*(c + d*x)))^n], x] /; FreeQ[{F, a, b, c, d, e, n}, x] && GtQ[a, 0]

Rule 2438

Int[Log[(c_.)*((d_) + (e_.)*(x_)^(n_.))]/(x_), x_Symbol] :> Simp[-PolyLog[2, (-c)*e*x^n]/n, x] /; FreeQ[{c, d,
e, n}, x] && EqQ[c*d, 1]

Rule 3400

Int[((c_.) + (d_.)*(x_))^(m_.)*((a_) + (b_.)*sin[(e_.) + (f_.)*(x_)])^(n_), x_Symbol] :> Dist[(2*a)^IntPart[n]
*((a + b*Sin[e + f*x])^FracPart[n]/Sin[e/2 + a*(Pi/(4*b)) + f*(x/2)]^(2*FracPart[n])), Int[(c + d*x)^m*Sin[e/2
+ a*(Pi/(4*b)) + f*(x/2)]^(2*n), x], x] /; FreeQ[{a, b, c, d, e, f, m}, x] && EqQ[a^2 - b^2, 0] && IntegerQ[n
+ 1/2] && (GtQ[n, 0] || IGtQ[m, 0])

Rule 4268

Int[csc[(e_.) + (f_.)*(x_)]*((c_.) + (d_.)*(x_))^(m_.), x_Symbol] :> Simp[-2*(c + d*x)^m*(ArcTanh[E^(I*(e + f*
x))]/f), x] + (-Dist[d*(m/f), Int[(c + d*x)^(m - 1)*Log[1 - E^(I*(e + f*x))], x], x] + Dist[d*(m/f), Int[(c +
d*x)^(m - 1)*Log[1 + E^(I*(e + f*x))], x], x]) /; FreeQ[{c, d, e, f}, x] && IGtQ[m, 0]

Rubi steps

\begin {align*} \int \frac {x}{\sqrt {a-a \cos (x)}} \, dx &=\frac {\sin \left (\frac {x}{2}\right ) \int x \csc \left (\frac {x}{2}\right ) \, dx}{\sqrt {a-a \cos (x)}}\\ &=-\frac {4 x \tanh ^{-1}\left (e^{\frac {i x}{2}}\right ) \sin \left (\frac {x}{2}\right )}{\sqrt {a-a \cos (x)}}-\frac {\left (2 \sin \left (\frac {x}{2}\right )\right ) \int \log \left (1-e^{\frac {i x}{2}}\right ) \, dx}{\sqrt {a-a \cos (x)}}+\frac {\left (2 \sin \left (\frac {x}{2}\right )\right ) \int \log \left (1+e^{\frac {i x}{2}}\right ) \, dx}{\sqrt {a-a \cos (x)}}\\ &=-\frac {4 x \tanh ^{-1}\left (e^{\frac {i x}{2}}\right ) \sin \left (\frac {x}{2}\right )}{\sqrt {a-a \cos (x)}}+\frac {\left (4 i \sin \left (\frac {x}{2}\right )\right ) \text {Subst}\left (\int \frac {\log (1-x)}{x} \, dx,x,e^{\frac {i x}{2}}\right )}{\sqrt {a-a \cos (x)}}-\frac {\left (4 i \sin \left (\frac {x}{2}\right )\right ) \text {Subst}\left (\int \frac {\log (1+x)}{x} \, dx,x,e^{\frac {i x}{2}}\right )}{\sqrt {a-a \cos (x)}}\\ &=-\frac {4 x \tanh ^{-1}\left (e^{\frac {i x}{2}}\right ) \sin \left (\frac {x}{2}\right )}{\sqrt {a-a \cos (x)}}+\frac {4 i \text {Li}_2\left (-e^{\frac {i x}{2}}\right ) \sin \left (\frac {x}{2}\right )}{\sqrt {a-a \cos (x)}}-\frac {4 i \text {Li}_2\left (e^{\frac {i x}{2}}\right ) \sin \left (\frac {x}{2}\right )}{\sqrt {a-a \cos (x)}}\\ \end {align*}

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Mathematica [A]
time = 0.03, size = 83, normalized size = 0.86 \begin {gather*} \frac {2 \left (x \left (\log \left (1-e^{\frac {i x}{2}}\right )-\log \left (1+e^{\frac {i x}{2}}\right )\right )+2 i \text {PolyLog}\left (2,-e^{\frac {i x}{2}}\right )-2 i \text {PolyLog}\left (2,e^{\frac {i x}{2}}\right )\right ) \sin \left (\frac {x}{2}\right )}{\sqrt {a-a \cos (x)}} \end {gather*}

Antiderivative was successfully verified.

[In]

Integrate[x/Sqrt[a - a*Cos[x]],x]

[Out]

(2*(x*(Log[1 - E^((I/2)*x)] - Log[1 + E^((I/2)*x)]) + (2*I)*PolyLog[2, -E^((I/2)*x)] - (2*I)*PolyLog[2, E^((I/
2)*x)])*Sin[x/2])/Sqrt[a - a*Cos[x]]

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Maple [F]
time = 0.03, size = 0, normalized size = 0.00 \[\int \frac {x}{\sqrt {a -a \cos \left (x \right )}}\, dx\]

Verification of antiderivative is not currently implemented for this CAS.

[In]

int(x/(a-a*cos(x))^(1/2),x)

[Out]

int(x/(a-a*cos(x))^(1/2),x)

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Maxima [F]
time = 0.00, size = 0, normalized size = 0.00 \begin {gather*} \text {Failed to integrate} \end {gather*}

Verification of antiderivative is not currently implemented for this CAS.

[In]

integrate(x/(a-a*cos(x))^(1/2),x, algorithm="maxima")

[Out]

integrate(x/sqrt(-a*cos(x) + a), x)

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Fricas [F]
time = 0.00, size = 0, normalized size = 0.00 \begin {gather*} \text {could not integrate} \end {gather*}

Verification of antiderivative is not currently implemented for this CAS.

[In]

integrate(x/(a-a*cos(x))^(1/2),x, algorithm="fricas")

[Out]

integral(-sqrt(-a*cos(x) + a)*x/(a*cos(x) - a), x)

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Sympy [F]
time = 0.00, size = 0, normalized size = 0.00 \begin {gather*} \int \frac {x}{\sqrt {- a \left (\cos {\left (x \right )} - 1\right )}}\, dx \end {gather*}

Verification of antiderivative is not currently implemented for this CAS.

[In]

integrate(x/(a-a*cos(x))**(1/2),x)

[Out]

Integral(x/sqrt(-a*(cos(x) - 1)), x)

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Giac [F]
time = 0.00, size = 0, normalized size = 0.00 \begin {gather*} \text {could not integrate} \end {gather*}

Verification of antiderivative is not currently implemented for this CAS.

[In]

integrate(x/(a-a*cos(x))^(1/2),x, algorithm="giac")

[Out]

integrate(x/sqrt(-a*cos(x) + a), x)

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Mupad [F]
time = 0.00, size = -1, normalized size = -0.01 \begin {gather*} \int \frac {x}{\sqrt {a-a\,\cos \left (x\right )}} \,d x \end {gather*}

Verification of antiderivative is not currently implemented for this CAS.

[In]

int(x/(a - a*cos(x))^(1/2),x)

[Out]

int(x/(a - a*cos(x))^(1/2), x)

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