Integrand size = 12, antiderivative size = 121 \[ \int \left (a+b \cos ^2(x)\right )^{3/2} \, dx=\frac {2 (2 a+b) \sqrt {a+b \cos ^2(x)} E\left (\frac {\pi }{2}+x|-\frac {b}{a}\right )}{3 \sqrt {1+\frac {b \cos ^2(x)}{a}}}-\frac {a (a+b) \sqrt {1+\frac {b \cos ^2(x)}{a}} \operatorname {EllipticF}\left (\frac {\pi }{2}+x,-\frac {b}{a}\right )}{3 \sqrt {a+b \cos ^2(x)}}+\frac {1}{3} b \cos (x) \sqrt {a+b \cos ^2(x)} \sin (x) \]
1/3*b*cos(x)*sin(x)*(a+b*cos(x)^2)^(1/2)-2/3*(2*a+b)*(sin(x)^2)^(1/2)/sin( x)*EllipticE(cos(x),(-b/a)^(1/2))*(a+b*cos(x)^2)^(1/2)/(1+b*cos(x)^2/a)^(1 /2)+1/3*a*(a+b)*(sin(x)^2)^(1/2)/sin(x)*EllipticF(cos(x),(-b/a)^(1/2))*(1+ b*cos(x)^2/a)^(1/2)/(a+b*cos(x)^2)^(1/2)
Time = 0.36 (sec) , antiderivative size = 123, normalized size of antiderivative = 1.02 \[ \int \left (a+b \cos ^2(x)\right )^{3/2} \, dx=\frac {8 \left (2 a^2+3 a b+b^2\right ) \sqrt {\frac {2 a+b+b \cos (2 x)}{a+b}} E\left (x\left |\frac {b}{a+b}\right .\right )-4 a (a+b) \sqrt {\frac {2 a+b+b \cos (2 x)}{a+b}} \operatorname {EllipticF}\left (x,\frac {b}{a+b}\right )+\sqrt {2} b (2 a+b+b \cos (2 x)) \sin (2 x)}{12 \sqrt {2 a+b+b \cos (2 x)}} \]
(8*(2*a^2 + 3*a*b + b^2)*Sqrt[(2*a + b + b*Cos[2*x])/(a + b)]*EllipticE[x, b/(a + b)] - 4*a*(a + b)*Sqrt[(2*a + b + b*Cos[2*x])/(a + b)]*EllipticF[x , b/(a + b)] + Sqrt[2]*b*(2*a + b + b*Cos[2*x])*Sin[2*x])/(12*Sqrt[2*a + b + b*Cos[2*x]])
Time = 0.69 (sec) , antiderivative size = 122, normalized size of antiderivative = 1.01, number of steps used = 11, number of rules used = 11, \(\frac {\text {number of rules}}{\text {integrand size}}\) = 0.917, Rules used = {3042, 3659, 3042, 3651, 3042, 3657, 3042, 3656, 3662, 3042, 3661}
Below are the steps used by Rubi to obtain the solution. The rule number used for the transformation is given above next to the arrow. The rules definitions used are listed below.
\(\displaystyle \int \left (a+b \cos ^2(x)\right )^{3/2} \, dx\) |
\(\Big \downarrow \) 3042 |
\(\displaystyle \int \left (a+b \sin \left (x+\frac {\pi }{2}\right )^2\right )^{3/2}dx\) |
\(\Big \downarrow \) 3659 |
\(\displaystyle \frac {1}{3} \int \frac {2 b (2 a+b) \cos ^2(x)+a (3 a+b)}{\sqrt {b \cos ^2(x)+a}}dx+\frac {1}{3} b \sin (x) \cos (x) \sqrt {a+b \cos ^2(x)}\) |
\(\Big \downarrow \) 3042 |
\(\displaystyle \frac {1}{3} \int \frac {2 b (2 a+b) \sin \left (x+\frac {\pi }{2}\right )^2+a (3 a+b)}{\sqrt {b \sin \left (x+\frac {\pi }{2}\right )^2+a}}dx+\frac {1}{3} b \sin (x) \cos (x) \sqrt {a+b \cos ^2(x)}\) |
\(\Big \downarrow \) 3651 |
\(\displaystyle \frac {1}{3} \left (2 (2 a+b) \int \sqrt {b \cos ^2(x)+a}dx-a (a+b) \int \frac {1}{\sqrt {b \cos ^2(x)+a}}dx\right )+\frac {1}{3} b \sin (x) \cos (x) \sqrt {a+b \cos ^2(x)}\) |
\(\Big \downarrow \) 3042 |
\(\displaystyle \frac {1}{3} \left (2 (2 a+b) \int \sqrt {b \sin \left (x+\frac {\pi }{2}\right )^2+a}dx-a (a+b) \int \frac {1}{\sqrt {b \sin \left (x+\frac {\pi }{2}\right )^2+a}}dx\right )+\frac {1}{3} b \sin (x) \cos (x) \sqrt {a+b \cos ^2(x)}\) |
\(\Big \downarrow \) 3657 |
\(\displaystyle \frac {1}{3} \left (\frac {2 (2 a+b) \sqrt {a+b \cos ^2(x)} \int \sqrt {\frac {b \cos ^2(x)}{a}+1}dx}{\sqrt {\frac {b \cos ^2(x)}{a}+1}}-a (a+b) \int \frac {1}{\sqrt {b \sin \left (x+\frac {\pi }{2}\right )^2+a}}dx\right )+\frac {1}{3} b \sin (x) \cos (x) \sqrt {a+b \cos ^2(x)}\) |
\(\Big \downarrow \) 3042 |
\(\displaystyle \frac {1}{3} \left (\frac {2 (2 a+b) \sqrt {a+b \cos ^2(x)} \int \sqrt {\frac {b \sin \left (x+\frac {\pi }{2}\right )^2}{a}+1}dx}{\sqrt {\frac {b \cos ^2(x)}{a}+1}}-a (a+b) \int \frac {1}{\sqrt {b \sin \left (x+\frac {\pi }{2}\right )^2+a}}dx\right )+\frac {1}{3} b \sin (x) \cos (x) \sqrt {a+b \cos ^2(x)}\) |
\(\Big \downarrow \) 3656 |
\(\displaystyle \frac {1}{3} \left (\frac {2 (2 a+b) \sqrt {a+b \cos ^2(x)} E\left (x+\frac {\pi }{2}|-\frac {b}{a}\right )}{\sqrt {\frac {b \cos ^2(x)}{a}+1}}-a (a+b) \int \frac {1}{\sqrt {b \sin \left (x+\frac {\pi }{2}\right )^2+a}}dx\right )+\frac {1}{3} b \sin (x) \cos (x) \sqrt {a+b \cos ^2(x)}\) |
\(\Big \downarrow \) 3662 |
\(\displaystyle \frac {1}{3} \left (\frac {2 (2 a+b) \sqrt {a+b \cos ^2(x)} E\left (x+\frac {\pi }{2}|-\frac {b}{a}\right )}{\sqrt {\frac {b \cos ^2(x)}{a}+1}}-\frac {a (a+b) \sqrt {\frac {b \cos ^2(x)}{a}+1} \int \frac {1}{\sqrt {\frac {b \cos ^2(x)}{a}+1}}dx}{\sqrt {a+b \cos ^2(x)}}\right )+\frac {1}{3} b \sin (x) \cos (x) \sqrt {a+b \cos ^2(x)}\) |
\(\Big \downarrow \) 3042 |
\(\displaystyle \frac {1}{3} \left (\frac {2 (2 a+b) \sqrt {a+b \cos ^2(x)} E\left (x+\frac {\pi }{2}|-\frac {b}{a}\right )}{\sqrt {\frac {b \cos ^2(x)}{a}+1}}-\frac {a (a+b) \sqrt {\frac {b \cos ^2(x)}{a}+1} \int \frac {1}{\sqrt {\frac {b \sin \left (x+\frac {\pi }{2}\right )^2}{a}+1}}dx}{\sqrt {a+b \cos ^2(x)}}\right )+\frac {1}{3} b \sin (x) \cos (x) \sqrt {a+b \cos ^2(x)}\) |
\(\Big \downarrow \) 3661 |
\(\displaystyle \frac {1}{3} b \sin (x) \cos (x) \sqrt {a+b \cos ^2(x)}+\frac {1}{3} \left (\frac {2 (2 a+b) \sqrt {a+b \cos ^2(x)} E\left (x+\frac {\pi }{2}|-\frac {b}{a}\right )}{\sqrt {\frac {b \cos ^2(x)}{a}+1}}-\frac {a (a+b) \sqrt {\frac {b \cos ^2(x)}{a}+1} \operatorname {EllipticF}\left (x+\frac {\pi }{2},-\frac {b}{a}\right )}{\sqrt {a+b \cos ^2(x)}}\right )\) |
((2*(2*a + b)*Sqrt[a + b*Cos[x]^2]*EllipticE[Pi/2 + x, -(b/a)])/Sqrt[1 + ( b*Cos[x]^2)/a] - (a*(a + b)*Sqrt[1 + (b*Cos[x]^2)/a]*EllipticF[Pi/2 + x, - (b/a)])/Sqrt[a + b*Cos[x]^2])/3 + (b*Cos[x]*Sqrt[a + b*Cos[x]^2]*Sin[x])/3
3.1.60.3.1 Defintions of rubi rules used
Int[((A_.) + (B_.)*sin[(e_.) + (f_.)*(x_)]^2)/Sqrt[(a_) + (b_.)*sin[(e_.) + (f_.)*(x_)]^2], x_Symbol] :> Simp[B/b Int[Sqrt[a + b*Sin[e + f*x]^2], x] , x] + Simp[(A*b - a*B)/b Int[1/Sqrt[a + b*Sin[e + f*x]^2], x], x] /; Fre eQ[{a, b, e, f, A, B}, x]
Int[Sqrt[(a_) + (b_.)*sin[(e_.) + (f_.)*(x_)]^2], x_Symbol] :> Simp[(Sqrt[a ]/f)*EllipticE[e + f*x, -b/a], x] /; FreeQ[{a, b, e, f}, x] && GtQ[a, 0]
Int[Sqrt[(a_) + (b_.)*sin[(e_.) + (f_.)*(x_)]^2], x_Symbol] :> Simp[Sqrt[a + b*Sin[e + f*x]^2]/Sqrt[1 + b*(Sin[e + f*x]^2/a)] Int[Sqrt[1 + (b*Sin[e + f*x]^2)/a], x], x] /; FreeQ[{a, b, e, f}, x] && !GtQ[a, 0]
Int[((a_) + (b_.)*sin[(e_.) + (f_.)*(x_)]^2)^(p_), x_Symbol] :> Simp[(-b)*C os[e + f*x]*Sin[e + f*x]*((a + b*Sin[e + f*x]^2)^(p - 1)/(2*f*p)), x] + Sim p[1/(2*p) Int[(a + b*Sin[e + f*x]^2)^(p - 2)*Simp[a*(b + 2*a*p) + b*(2*a + b)*(2*p - 1)*Sin[e + f*x]^2, x], x], x] /; FreeQ[{a, b, e, f}, x] && NeQ[ a + b, 0] && GtQ[p, 1]
Int[1/Sqrt[(a_) + (b_.)*sin[(e_.) + (f_.)*(x_)]^2], x_Symbol] :> Simp[(1/(S qrt[a]*f))*EllipticF[e + f*x, -b/a], x] /; FreeQ[{a, b, e, f}, x] && GtQ[a, 0]
Int[1/Sqrt[(a_) + (b_.)*sin[(e_.) + (f_.)*(x_)]^2], x_Symbol] :> Simp[Sqrt[ 1 + b*(Sin[e + f*x]^2/a)]/Sqrt[a + b*Sin[e + f*x]^2] Int[1/Sqrt[1 + (b*Si n[e + f*x]^2)/a], x], x] /; FreeQ[{a, b, e, f}, x] && !GtQ[a, 0]
Time = 2.97 (sec) , antiderivative size = 192, normalized size of antiderivative = 1.59
method | result | size |
default | \(-\frac {-\frac {a^{2} \sqrt {\frac {1}{2}-\frac {\cos \left (2 x \right )}{2}}\, \sqrt {\frac {a +b \left (\cos ^{2}\left (x \right )\right )}{a}}\, F\left (\cos \left (x \right ), \sqrt {-\frac {b}{a}}\right )}{3}-\frac {a \sqrt {\frac {1}{2}-\frac {\cos \left (2 x \right )}{2}}\, \sqrt {\frac {a +b \left (\cos ^{2}\left (x \right )\right )}{a}}\, F\left (\cos \left (x \right ), \sqrt {-\frac {b}{a}}\right ) b}{3}+\frac {4 \sqrt {\frac {1}{2}-\frac {\cos \left (2 x \right )}{2}}\, \sqrt {\frac {a +b \left (\cos ^{2}\left (x \right )\right )}{a}}\, E\left (\cos \left (x \right ), \sqrt {-\frac {b}{a}}\right ) a^{2}}{3}+\frac {2 \sqrt {\frac {1}{2}-\frac {\cos \left (2 x \right )}{2}}\, \sqrt {\frac {a +b \left (\cos ^{2}\left (x \right )\right )}{a}}\, E\left (\cos \left (x \right ), \sqrt {-\frac {b}{a}}\right ) a b}{3}+\frac {\left (\cos ^{5}\left (x \right )\right ) b^{2}}{3}+\frac {b \left (\cos ^{3}\left (x \right )\right ) a}{3}-\frac {b^{2} \left (\cos ^{3}\left (x \right )\right )}{3}-\frac {b \cos \left (x \right ) a}{3}}{\sin \left (x \right ) \sqrt {a +b \left (\cos ^{2}\left (x \right )\right )}}\) | \(192\) |
-(-1/3*a^2*(sin(x)^2)^(1/2)*((a+b*cos(x)^2)/a)^(1/2)*EllipticF(cos(x),(-b/ a)^(1/2))-1/3*a*(sin(x)^2)^(1/2)*((a+b*cos(x)^2)/a)^(1/2)*EllipticF(cos(x) ,(-b/a)^(1/2))*b+4/3*(sin(x)^2)^(1/2)*((a+b*cos(x)^2)/a)^(1/2)*EllipticE(c os(x),(-b/a)^(1/2))*a^2+2/3*(sin(x)^2)^(1/2)*((a+b*cos(x)^2)/a)^(1/2)*Elli pticE(cos(x),(-b/a)^(1/2))*a*b+1/3*cos(x)^5*b^2+1/3*b*cos(x)^3*a-1/3*b^2*c os(x)^3-1/3*b*cos(x)*a)/sin(x)/(a+b*cos(x)^2)^(1/2)
\[ \int \left (a+b \cos ^2(x)\right )^{3/2} \, dx=\int { {\left (b \cos \left (x\right )^{2} + a\right )}^{\frac {3}{2}} \,d x } \]
\[ \int \left (a+b \cos ^2(x)\right )^{3/2} \, dx=\int \left (a + b \cos ^{2}{\left (x \right )}\right )^{\frac {3}{2}}\, dx \]
\[ \int \left (a+b \cos ^2(x)\right )^{3/2} \, dx=\int { {\left (b \cos \left (x\right )^{2} + a\right )}^{\frac {3}{2}} \,d x } \]
\[ \int \left (a+b \cos ^2(x)\right )^{3/2} \, dx=\int { {\left (b \cos \left (x\right )^{2} + a\right )}^{\frac {3}{2}} \,d x } \]
Timed out. \[ \int \left (a+b \cos ^2(x)\right )^{3/2} \, dx=\int {\left (b\,{\cos \left (x\right )}^2+a\right )}^{3/2} \,d x \]