3.101 \(\int x \cos ^3(x) \, dx\)

Optimal. Leaf size=33 \[ \frac{2}{3} x \sin (x)+\frac{\cos ^3(x)}{9}+\frac{2 \cos (x)}{3}+\frac{1}{3} x \sin (x) \cos ^2(x) \]

[Out]

(2*Cos[x])/3 + Cos[x]^3/9 + (2*x*Sin[x])/3 + (x*Cos[x]^2*Sin[x])/3

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Rubi [A]  time = 0.0230636, antiderivative size = 33, normalized size of antiderivative = 1., number of steps used = 3, number of rules used = 3, integrand size = 6, \(\frac{\text{number of rules}}{\text{integrand size}}\) = 0.5, Rules used = {3310, 3296, 2638} \[ \frac{2}{3} x \sin (x)+\frac{\cos ^3(x)}{9}+\frac{2 \cos (x)}{3}+\frac{1}{3} x \sin (x) \cos ^2(x) \]

Antiderivative was successfully verified.

[In]

Int[x*Cos[x]^3,x]

[Out]

(2*Cos[x])/3 + Cos[x]^3/9 + (2*x*Sin[x])/3 + (x*Cos[x]^2*Sin[x])/3

Rule 3310

Int[((c_.) + (d_.)*(x_))*((b_.)*sin[(e_.) + (f_.)*(x_)])^(n_), x_Symbol] :> Simp[(d*(b*Sin[e + f*x])^n)/(f^2*n
^2), x] + (Dist[(b^2*(n - 1))/n, Int[(c + d*x)*(b*Sin[e + f*x])^(n - 2), x], x] - Simp[(b*(c + d*x)*Cos[e + f*
x]*(b*Sin[e + f*x])^(n - 1))/(f*n), x]) /; FreeQ[{b, c, d, e, f}, x] && GtQ[n, 1]

Rule 3296

Int[((c_.) + (d_.)*(x_))^(m_.)*sin[(e_.) + (f_.)*(x_)], x_Symbol] :> -Simp[((c + d*x)^m*Cos[e + f*x])/f, x] +
Dist[(d*m)/f, Int[(c + d*x)^(m - 1)*Cos[e + f*x], x], x] /; FreeQ[{c, d, e, f}, x] && GtQ[m, 0]

Rule 2638

Int[sin[(c_.) + (d_.)*(x_)], x_Symbol] :> -Simp[Cos[c + d*x]/d, x] /; FreeQ[{c, d}, x]

Rubi steps

\begin{align*} \int x \cos ^3(x) \, dx &=\frac{\cos ^3(x)}{9}+\frac{1}{3} x \cos ^2(x) \sin (x)+\frac{2}{3} \int x \cos (x) \, dx\\ &=\frac{\cos ^3(x)}{9}+\frac{2}{3} x \sin (x)+\frac{1}{3} x \cos ^2(x) \sin (x)-\frac{2}{3} \int \sin (x) \, dx\\ &=\frac{2 \cos (x)}{3}+\frac{\cos ^3(x)}{9}+\frac{2}{3} x \sin (x)+\frac{1}{3} x \cos ^2(x) \sin (x)\\ \end{align*}

Mathematica [A]  time = 0.00813, size = 31, normalized size = 0.94 \[ \frac{3}{4} x \sin (x)+\frac{1}{12} x \sin (3 x)+\frac{3 \cos (x)}{4}+\frac{1}{36} \cos (3 x) \]

Antiderivative was successfully verified.

[In]

Integrate[x*Cos[x]^3,x]

[Out]

(3*Cos[x])/4 + Cos[3*x]/36 + (3*x*Sin[x])/4 + (x*Sin[3*x])/12

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Maple [A]  time = 0.011, size = 23, normalized size = 0.7 \begin{align*}{\frac{x \left ( 2+ \left ( \cos \left ( x \right ) \right ) ^{2} \right ) \sin \left ( x \right ) }{3}}+{\frac{ \left ( \cos \left ( x \right ) \right ) ^{3}}{9}}+{\frac{2\,\cos \left ( x \right ) }{3}} \end{align*}

Verification of antiderivative is not currently implemented for this CAS.

[In]

int(x*cos(x)^3,x)

[Out]

1/3*x*(2+cos(x)^2)*sin(x)+1/9*cos(x)^3+2/3*cos(x)

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Maxima [A]  time = 0.951987, size = 31, normalized size = 0.94 \begin{align*} \frac{1}{12} \, x \sin \left (3 \, x\right ) + \frac{3}{4} \, x \sin \left (x\right ) + \frac{1}{36} \, \cos \left (3 \, x\right ) + \frac{3}{4} \, \cos \left (x\right ) \end{align*}

Verification of antiderivative is not currently implemented for this CAS.

[In]

integrate(x*cos(x)^3,x, algorithm="maxima")

[Out]

1/12*x*sin(3*x) + 3/4*x*sin(x) + 1/36*cos(3*x) + 3/4*cos(x)

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Fricas [A]  time = 1.77494, size = 80, normalized size = 2.42 \begin{align*} \frac{1}{9} \, \cos \left (x\right )^{3} + \frac{1}{3} \,{\left (x \cos \left (x\right )^{2} + 2 \, x\right )} \sin \left (x\right ) + \frac{2}{3} \, \cos \left (x\right ) \end{align*}

Verification of antiderivative is not currently implemented for this CAS.

[In]

integrate(x*cos(x)^3,x, algorithm="fricas")

[Out]

1/9*cos(x)^3 + 1/3*(x*cos(x)^2 + 2*x)*sin(x) + 2/3*cos(x)

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Sympy [A]  time = 0.60164, size = 39, normalized size = 1.18 \begin{align*} \frac{2 x \sin ^{3}{\left (x \right )}}{3} + x \sin{\left (x \right )} \cos ^{2}{\left (x \right )} + \frac{2 \sin ^{2}{\left (x \right )} \cos{\left (x \right )}}{3} + \frac{7 \cos ^{3}{\left (x \right )}}{9} \end{align*}

Verification of antiderivative is not currently implemented for this CAS.

[In]

integrate(x*cos(x)**3,x)

[Out]

2*x*sin(x)**3/3 + x*sin(x)*cos(x)**2 + 2*sin(x)**2*cos(x)/3 + 7*cos(x)**3/9

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Giac [A]  time = 1.06452, size = 31, normalized size = 0.94 \begin{align*} \frac{1}{12} \, x \sin \left (3 \, x\right ) + \frac{3}{4} \, x \sin \left (x\right ) + \frac{1}{36} \, \cos \left (3 \, x\right ) + \frac{3}{4} \, \cos \left (x\right ) \end{align*}

Verification of antiderivative is not currently implemented for this CAS.

[In]

integrate(x*cos(x)^3,x, algorithm="giac")

[Out]

1/12*x*sin(3*x) + 3/4*x*sin(x) + 1/36*cos(3*x) + 3/4*cos(x)