3.29.90 \(\int \frac {2}{(-4+x) \log (-8+2 x)} \, dx\)

Optimal. Leaf size=14 \[ 3+\log \left (\log ^2\left (-8+\log \left (e^{2 x}\right )\right )\right ) \]

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Rubi [A]  time = 0.04, antiderivative size = 11, normalized size of antiderivative = 0.79, number of steps used = 5, number of rules used = 4, integrand size = 15, \(\frac {\text {number of rules}}{\text {integrand size}}\) = 0.267, Rules used = {12, 2390, 2302, 29} \begin {gather*} 2 \log (\log (-2 (4-x))) \end {gather*}

Antiderivative was successfully verified.

[In]

Int[2/((-4 + x)*Log[-8 + 2*x]),x]

[Out]

2*Log[Log[-2*(4 - x)]]

Rule 12

Int[(a_)*(u_), x_Symbol] :> Dist[a, Int[u, x], x] /; FreeQ[a, x] &&  !MatchQ[u, (b_)*(v_) /; FreeQ[b, x]]

Rule 29

Int[(x_)^(-1), x_Symbol] :> Simp[Log[x], x]

Rule 2302

Int[((a_.) + Log[(c_.)*(x_)^(n_.)]*(b_.))^(p_.)/(x_), x_Symbol] :> Dist[1/(b*n), Subst[Int[x^p, x], x, a + b*L
og[c*x^n]], x] /; FreeQ[{a, b, c, n, p}, x]

Rule 2390

Int[((a_.) + Log[(c_.)*((d_) + (e_.)*(x_))^(n_.)]*(b_.))^(p_.)*((f_) + (g_.)*(x_))^(q_.), x_Symbol] :> Dist[1/
e, Subst[Int[((f*x)/d)^q*(a + b*Log[c*x^n])^p, x], x, d + e*x], x] /; FreeQ[{a, b, c, d, e, f, g, n, p, q}, x]
&& EqQ[e*f - d*g, 0]

Rubi steps

\begin {gather*} \begin {aligned} \text {integral} &=2 \int \frac {1}{(-4+x) \log (-8+2 x)} \, dx\\ &=\operatorname {Subst}\left (\int \frac {2}{x \log (x)} \, dx,x,-8+2 x\right )\\ &=2 \operatorname {Subst}\left (\int \frac {1}{x \log (x)} \, dx,x,-8+2 x\right )\\ &=2 \operatorname {Subst}\left (\int \frac {1}{x} \, dx,x,\log (2 (-4+x))\right )\\ &=2 \log (\log (-2 (4-x)))\\ \end {aligned} \end {gather*}

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Mathematica [A]  time = 0.03, size = 9, normalized size = 0.64 \begin {gather*} 2 \log (\log (2 (-4+x))) \end {gather*}

Antiderivative was successfully verified.

[In]

Integrate[2/((-4 + x)*Log[-8 + 2*x]),x]

[Out]

2*Log[Log[2*(-4 + x)]]

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fricas [A]  time = 0.56, size = 9, normalized size = 0.64 \begin {gather*} 2 \, \log \left (\log \left (2 \, x - 8\right )\right ) \end {gather*}

Verification of antiderivative is not currently implemented for this CAS.

[In]

integrate(2/(x-4)/log(2*x-8),x, algorithm="fricas")

[Out]

2*log(log(2*x - 8))

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giac [A]  time = 0.31, size = 9, normalized size = 0.64 \begin {gather*} 2 \, \log \left (\log \left (2 \, x - 8\right )\right ) \end {gather*}

Verification of antiderivative is not currently implemented for this CAS.

[In]

integrate(2/(x-4)/log(2*x-8),x, algorithm="giac")

[Out]

2*log(log(2*x - 8))

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maple [A]  time = 0.46, size = 10, normalized size = 0.71

method	result	size
derivativedivides	\(2 \ln \left (\ln \left (2 x -8\right )\right )\)	\(10\)
default	\(2 \ln \left (\ln \left (2 x -8\right )\right )\)	\(10\)
norman	\(2 \ln \left (\ln \left (2 x -8\right )\right )\)	\(10\)
risch	\(2 \ln \left (\ln \left (2 x -8\right )\right )\)	\(10\)

Verification of antiderivative is not currently implemented for this CAS.

[In]

int(2/(x-4)/ln(2*x-8),x,method=_RETURNVERBOSE)

[Out]

2*ln(ln(2*x-8))

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maxima [A]  time = 0.38, size = 9, normalized size = 0.64 \begin {gather*} 2 \, \log \left (\log \left (2 \, x - 8\right )\right ) \end {gather*}

Verification of antiderivative is not currently implemented for this CAS.

[In]

integrate(2/(x-4)/log(2*x-8),x, algorithm="maxima")

[Out]

2*log(log(2*x - 8))

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mupad [B]  time = 1.84, size = 9, normalized size = 0.64 \begin {gather*} 2\,\ln \left (\ln \left (2\,x-8\right )\right ) \end {gather*}

Verification of antiderivative is not currently implemented for this CAS.

[In]

int(2/(log(2*x - 8)*(x - 4)),x)

[Out]

2*log(log(2*x - 8))

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sympy [A]  time = 0.10, size = 8, normalized size = 0.57 \begin {gather*} 2 \log {\left (\log {\left (2 x - 8 \right )} \right )} \end {gather*}

Verification of antiderivative is not currently implemented for this CAS.

[In]

integrate(2/(x-4)/ln(2*x-8),x)

[Out]

2*log(log(2*x - 8))

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