3.5 \(\int \cos ^{-1}(a x) \, dx\)

Optimal. Leaf size=26 \[ x \cos ^{-1}(a x)-\frac {\sqrt {1-a^2 x^2}}{a} \]

[Out]

x*arccos(a*x)-(-a^2*x^2+1)^(1/2)/a

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Rubi [A]  time = 0.01, antiderivative size = 26, normalized size of antiderivative = 1.00, number of steps used = 2, number of rules used = 2, integrand size = 4, \(\frac {\text {number of rules}}{\text {integrand size}}\) = 0.500, Rules used = {4620, 261} \[ x \cos ^{-1}(a x)-\frac {\sqrt {1-a^2 x^2}}{a} \]

Antiderivative was successfully verified.

[In]

Int[ArcCos[a*x],x]

[Out]

-(Sqrt[1 - a^2*x^2]/a) + x*ArcCos[a*x]

Rule 261

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

Rule 4620

Int[((a_.) + ArcCos[(c_.)*(x_)]*(b_.))^(n_.), x_Symbol] :> Simp[x*(a + b*ArcCos[c*x])^n, x] + Dist[b*c*n, Int[
(x*(a + b*ArcCos[c*x])^(n - 1))/Sqrt[1 - c^2*x^2], x], x] /; FreeQ[{a, b, c}, x] && GtQ[n, 0]

Rubi steps

\begin {align*} \int \cos ^{-1}(a x) \, dx &=x \cos ^{-1}(a x)+a \int \frac {x}{\sqrt {1-a^2 x^2}} \, dx\\ &=-\frac {\sqrt {1-a^2 x^2}}{a}+x \cos ^{-1}(a x)\\ \end {align*}

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Mathematica [A]  time = 0.01, size = 26, normalized size = 1.00 \[ x \cos ^{-1}(a x)-\frac {\sqrt {1-a^2 x^2}}{a} \]

Antiderivative was successfully verified.

[In]

Integrate[ArcCos[a*x],x]

[Out]

-(Sqrt[1 - a^2*x^2]/a) + x*ArcCos[a*x]

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fricas [A]  time = 0.47, size = 26, normalized size = 1.00 \[ \frac {a x \arccos \left (a x\right ) - \sqrt {-a^{2} x^{2} + 1}}{a} \]

Verification of antiderivative is not currently implemented for this CAS.

[In]

integrate(arccos(a*x),x, algorithm="fricas")

[Out]

(a*x*arccos(a*x) - sqrt(-a^2*x^2 + 1))/a

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giac [A]  time = 0.97, size = 26, normalized size = 1.00 \[ \frac {a x \arccos \left (a x\right ) - \sqrt {-a^{2} x^{2} + 1}}{a} \]

Verification of antiderivative is not currently implemented for this CAS.

[In]

integrate(arccos(a*x),x, algorithm="giac")

[Out]

(a*x*arccos(a*x) - sqrt(-a^2*x^2 + 1))/a

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maple [A]  time = 0.00, size = 27, normalized size = 1.04 \[ \frac {a x \arccos \left (a x \right )-\sqrt {-a^{2} x^{2}+1}}{a} \]

Verification of antiderivative is not currently implemented for this CAS.

[In]

int(arccos(a*x),x)

[Out]

1/a*(a*x*arccos(a*x)-(-a^2*x^2+1)^(1/2))

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maxima [A]  time = 0.40, size = 26, normalized size = 1.00 \[ \frac {a x \arccos \left (a x\right ) - \sqrt {-a^{2} x^{2} + 1}}{a} \]

Verification of antiderivative is not currently implemented for this CAS.

[In]

integrate(arccos(a*x),x, algorithm="maxima")

[Out]

(a*x*arccos(a*x) - sqrt(-a^2*x^2 + 1))/a

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mupad [B]  time = 0.07, size = 24, normalized size = 0.92 \[ x\,\mathrm {acos}\left (a\,x\right )-\frac {\sqrt {1-a^2\,x^2}}{a} \]

Verification of antiderivative is not currently implemented for this CAS.

[In]

int(acos(a*x),x)

[Out]

x*acos(a*x) - (1 - a^2*x^2)^(1/2)/a

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sympy [A]  time = 0.12, size = 24, normalized size = 0.92 \[ \begin {cases} x \operatorname {acos}{\left (a x \right )} - \frac {\sqrt {- a^{2} x^{2} + 1}}{a} & \text {for}\: a \neq 0 \\\frac {\pi x}{2} & \text {otherwise} \end {cases} \]

Verification of antiderivative is not currently implemented for this CAS.

[In]

integrate(acos(a*x),x)

[Out]

Piecewise((x*acos(a*x) - sqrt(-a**2*x**2 + 1)/a, Ne(a, 0)), (pi*x/2, True))

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