\(\int \frac {\text {csch}^3(x)}{a+b \cosh ^2(x)} \, dx\) [11]

Optimal result
Mathematica [C] (verified)
Rubi [A] (verified)
Maple [A] (verified)
Fricas [B] (verification not implemented)
Sympy [F]
Maxima [F]
Giac [F(-2)]
Mupad [B] (verification not implemented)
Reduce [B] (verification not implemented)

Optimal result

Integrand size = 15, antiderivative size = 61 \[ \int \frac {\text {csch}^3(x)}{a+b \cosh ^2(x)} \, dx=\frac {b^{3/2} \arctan \left (\frac {\sqrt {b} \cosh (x)}{\sqrt {a}}\right )}{\sqrt {a} (a+b)^2}+\frac {(a+3 b) \text {arctanh}(\cosh (x))}{2 (a+b)^2}-\frac {\coth (x) \text {csch}(x)}{2 (a+b)} \] Output:

b^(3/2)*arctan(b^(1/2)*cosh(x)/a^(1/2))/a^(1/2)/(a+b)^2+1/2*(a+3*b)*arctan 
h(cosh(x))/(a+b)^2-coth(x)*csch(x)/(2*a+2*b)
 

Mathematica [C] (verified)

Result contains complex when optimal does not.

Time = 0.30 (sec) , antiderivative size = 154, normalized size of antiderivative = 2.52 \[ \int \frac {\text {csch}^3(x)}{a+b \cosh ^2(x)} \, dx=\frac {8 b^{3/2} \arctan \left (\frac {\sqrt {b}-i \sqrt {a+b} \tanh \left (\frac {x}{2}\right )}{\sqrt {a}}\right )+8 b^{3/2} \arctan \left (\frac {\sqrt {b}+i \sqrt {a+b} \tanh \left (\frac {x}{2}\right )}{\sqrt {a}}\right )-\sqrt {a} (a+b) \text {csch}^2\left (\frac {x}{2}\right )+4 \sqrt {a} (a+3 b) \left (\log \left (\cosh \left (\frac {x}{2}\right )\right )-\log \left (\sinh \left (\frac {x}{2}\right )\right )\right )-\sqrt {a} (a+b) \text {sech}^2\left (\frac {x}{2}\right )}{8 \sqrt {a} (a+b)^2} \] Input:

Integrate[Csch[x]^3/(a + b*Cosh[x]^2),x]
 

Output:

(8*b^(3/2)*ArcTan[(Sqrt[b] - I*Sqrt[a + b]*Tanh[x/2])/Sqrt[a]] + 8*b^(3/2) 
*ArcTan[(Sqrt[b] + I*Sqrt[a + b]*Tanh[x/2])/Sqrt[a]] - Sqrt[a]*(a + b)*Csc 
h[x/2]^2 + 4*Sqrt[a]*(a + 3*b)*(Log[Cosh[x/2]] - Log[Sinh[x/2]]) - Sqrt[a] 
*(a + b)*Sech[x/2]^2)/(8*Sqrt[a]*(a + b)^2)
 

Rubi [A] (verified)

Time = 0.28 (sec) , antiderivative size = 77, normalized size of antiderivative = 1.26, number of steps used = 8, number of rules used = 7, \(\frac {\text {number of rules}}{\text {integrand size}}\) = 0.467, Rules used = {3042, 26, 3669, 316, 397, 218, 219}

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.

\(\displaystyle \int \frac {\text {csch}^3(x)}{a+b \cosh ^2(x)} \, dx\)

\(\Big \downarrow \) 3042

\(\displaystyle \int \frac {i}{\cos \left (\frac {\pi }{2}+i x\right )^3 \left (a+b \sin \left (\frac {\pi }{2}+i x\right )^2\right )}dx\)

\(\Big \downarrow \) 26

\(\displaystyle i \int \frac {1}{\cos \left (i x+\frac {\pi }{2}\right )^3 \left (b \sin \left (i x+\frac {\pi }{2}\right )^2+a\right )}dx\)

\(\Big \downarrow \) 3669

\(\displaystyle \int \frac {1}{\left (1-\cosh ^2(x)\right )^2 \left (a+b \cosh ^2(x)\right )}d\cosh (x)\)

\(\Big \downarrow \) 316

\(\displaystyle \frac {\int \frac {b \cosh ^2(x)+a+2 b}{\left (1-\cosh ^2(x)\right ) \left (b \cosh ^2(x)+a\right )}d\cosh (x)}{2 (a+b)}+\frac {\cosh (x)}{2 (a+b) \left (1-\cosh ^2(x)\right )}\)

\(\Big \downarrow \) 397

\(\displaystyle \frac {\frac {2 b^2 \int \frac {1}{b \cosh ^2(x)+a}d\cosh (x)}{a+b}+\frac {(a+3 b) \int \frac {1}{1-\cosh ^2(x)}d\cosh (x)}{a+b}}{2 (a+b)}+\frac {\cosh (x)}{2 (a+b) \left (1-\cosh ^2(x)\right )}\)

\(\Big \downarrow \) 218

\(\displaystyle \frac {\frac {(a+3 b) \int \frac {1}{1-\cosh ^2(x)}d\cosh (x)}{a+b}+\frac {2 b^{3/2} \arctan \left (\frac {\sqrt {b} \cosh (x)}{\sqrt {a}}\right )}{\sqrt {a} (a+b)}}{2 (a+b)}+\frac {\cosh (x)}{2 (a+b) \left (1-\cosh ^2(x)\right )}\)

\(\Big \downarrow \) 219

\(\displaystyle \frac {\frac {2 b^{3/2} \arctan \left (\frac {\sqrt {b} \cosh (x)}{\sqrt {a}}\right )}{\sqrt {a} (a+b)}+\frac {(a+3 b) \text {arctanh}(\cosh (x))}{a+b}}{2 (a+b)}+\frac {\cosh (x)}{2 (a+b) \left (1-\cosh ^2(x)\right )}\)

Input:

Int[Csch[x]^3/(a + b*Cosh[x]^2),x]
 

Output:

((2*b^(3/2)*ArcTan[(Sqrt[b]*Cosh[x])/Sqrt[a]])/(Sqrt[a]*(a + b)) + ((a + 3 
*b)*ArcTanh[Cosh[x]])/(a + b))/(2*(a + b)) + Cosh[x]/(2*(a + b)*(1 - Cosh[ 
x]^2))
 

Defintions of rubi rules used

rule 26
Int[(Complex[0, a_])*(Fx_), x_Symbol] :> Simp[(Complex[Identity[0], a])   I 
nt[Fx, x], x] /; FreeQ[a, x] && EqQ[a^2, 1]
 

rule 218
Int[((a_) + (b_.)*(x_)^2)^(-1), x_Symbol] :> Simp[(Rt[a/b, 2]/a)*ArcTan[x/R 
t[a/b, 2]], x] /; FreeQ[{a, b}, x] && PosQ[a/b]
 

rule 219
Int[((a_) + (b_.)*(x_)^2)^(-1), x_Symbol] :> Simp[(1/(Rt[a, 2]*Rt[-b, 2]))* 
ArcTanh[Rt[-b, 2]*(x/Rt[a, 2])], x] /; FreeQ[{a, b}, x] && NegQ[a/b] && (Gt 
Q[a, 0] || LtQ[b, 0])
 

rule 316
Int[((a_) + (b_.)*(x_)^2)^(p_)*((c_) + (d_.)*(x_)^2)^(q_), x_Symbol] :> Sim 
p[(-b)*x*(a + b*x^2)^(p + 1)*((c + d*x^2)^(q + 1)/(2*a*(p + 1)*(b*c - a*d)) 
), x] + Simp[1/(2*a*(p + 1)*(b*c - a*d))   Int[(a + b*x^2)^(p + 1)*(c + d*x 
^2)^q*Simp[b*c + 2*(p + 1)*(b*c - a*d) + d*b*(2*(p + q + 2) + 1)*x^2, x], x 
], x] /; FreeQ[{a, b, c, d, q}, x] && NeQ[b*c - a*d, 0] && LtQ[p, -1] &&  ! 
( !IntegerQ[p] && IntegerQ[q] && LtQ[q, -1]) && IntBinomialQ[a, b, c, d, 2, 
 p, q, x]
 

rule 397
Int[((e_) + (f_.)*(x_)^2)/(((a_) + (b_.)*(x_)^2)*((c_) + (d_.)*(x_)^2)), x_ 
Symbol] :> Simp[(b*e - a*f)/(b*c - a*d)   Int[1/(a + b*x^2), x], x] - Simp[ 
(d*e - c*f)/(b*c - a*d)   Int[1/(c + d*x^2), x], x] /; FreeQ[{a, b, c, d, e 
, f}, x]
 

rule 3042
Int[u_, x_Symbol] :> Int[DeactivateTrig[u, x], x] /; FunctionOfTrigOfLinear 
Q[u, x]
 

rule 3669
Int[cos[(e_.) + (f_.)*(x_)]^(m_.)*((a_) + (b_.)*sin[(e_.) + (f_.)*(x_)]^2)^ 
(p_.), x_Symbol] :> With[{ff = FreeFactors[Sin[e + f*x], x]}, Simp[ff/f   S 
ubst[Int[(1 - ff^2*x^2)^((m - 1)/2)*(a + b*ff^2*x^2)^p, x], x, Sin[e + f*x] 
/ff], x]] /; FreeQ[{a, b, e, f, p}, x] && IntegerQ[(m - 1)/2]
 
Maple [A] (verified)

Time = 12.19 (sec) , antiderivative size = 87, normalized size of antiderivative = 1.43

method result size
default \(\frac {\tanh \left (\frac {x}{2}\right )^{2}}{8 a +8 b}+\frac {b^{2} \arctan \left (\frac {2 \left (a +b \right ) \tanh \left (\frac {x}{2}\right )^{2}-2 a +2 b}{4 \sqrt {a b}}\right )}{\left (a +b \right )^{2} \sqrt {a b}}-\frac {1}{8 \left (a +b \right ) \tanh \left (\frac {x}{2}\right )^{2}}+\frac {\left (-2 a -6 b \right ) \ln \left (\tanh \left (\frac {x}{2}\right )\right )}{4 \left (a +b \right )^{2}}\) \(87\)
risch \(-\frac {{\mathrm e}^{x} \left ({\mathrm e}^{2 x}+1\right )}{\left ({\mathrm e}^{2 x}-1\right )^{2} \left (a +b \right )}+\frac {a \ln \left ({\mathrm e}^{x}+1\right )}{2 a^{2}+4 a b +2 b^{2}}+\frac {3 \ln \left ({\mathrm e}^{x}+1\right ) b}{2 \left (a^{2}+2 a b +b^{2}\right )}-\frac {\ln \left ({\mathrm e}^{x}-1\right ) a}{2 \left (a^{2}+2 a b +b^{2}\right )}-\frac {3 \ln \left ({\mathrm e}^{x}-1\right ) b}{2 \left (a^{2}+2 a b +b^{2}\right )}+\frac {\sqrt {-a b}\, b \ln \left ({\mathrm e}^{2 x}+\frac {2 \sqrt {-a b}\, {\mathrm e}^{x}}{b}+1\right )}{2 a \left (a +b \right )^{2}}-\frac {\sqrt {-a b}\, b \ln \left ({\mathrm e}^{2 x}-\frac {2 \sqrt {-a b}\, {\mathrm e}^{x}}{b}+1\right )}{2 a \left (a +b \right )^{2}}\) \(183\)

Input:

int(csch(x)^3/(a+b*cosh(x)^2),x,method=_RETURNVERBOSE)
 

Output:

1/8*tanh(1/2*x)^2/(a+b)+1/(a+b)^2*b^2/(a*b)^(1/2)*arctan(1/4*(2*(a+b)*tanh 
(1/2*x)^2-2*a+2*b)/(a*b)^(1/2))-1/8/(a+b)/tanh(1/2*x)^2+1/4/(a+b)^2*(-2*a- 
6*b)*ln(tanh(1/2*x))
 

Fricas [B] (verification not implemented)

Leaf count of result is larger than twice the leaf count of optimal. 638 vs. \(2 (49) = 98\).

Time = 0.13 (sec) , antiderivative size = 1332, normalized size of antiderivative = 21.84 \[ \int \frac {\text {csch}^3(x)}{a+b \cosh ^2(x)} \, dx=\text {Too large to display} \] Input:

integrate(csch(x)^3/(a+b*cosh(x)^2),x, algorithm="fricas")
 

Output:

[-1/2*(2*(a + b)*cosh(x)^3 + 6*(a + b)*cosh(x)*sinh(x)^2 + 2*(a + b)*sinh( 
x)^3 - (b*cosh(x)^4 + 4*b*cosh(x)*sinh(x)^3 + b*sinh(x)^4 - 2*b*cosh(x)^2 
+ 2*(3*b*cosh(x)^2 - b)*sinh(x)^2 + 4*(b*cosh(x)^3 - b*cosh(x))*sinh(x) + 
b)*sqrt(-b/a)*log((b*cosh(x)^4 + 4*b*cosh(x)*sinh(x)^3 + b*sinh(x)^4 - 2*( 
2*a - b)*cosh(x)^2 + 2*(3*b*cosh(x)^2 - 2*a + b)*sinh(x)^2 + 4*(b*cosh(x)^ 
3 - (2*a - b)*cosh(x))*sinh(x) + 4*(a*cosh(x)^3 + 3*a*cosh(x)*sinh(x)^2 + 
a*sinh(x)^3 + a*cosh(x) + (3*a*cosh(x)^2 + a)*sinh(x))*sqrt(-b/a) + b)/(b* 
cosh(x)^4 + 4*b*cosh(x)*sinh(x)^3 + b*sinh(x)^4 + 2*(2*a + b)*cosh(x)^2 + 
2*(3*b*cosh(x)^2 + 2*a + b)*sinh(x)^2 + 4*(b*cosh(x)^3 + (2*a + b)*cosh(x) 
)*sinh(x) + b)) + 2*(a + b)*cosh(x) - ((a + 3*b)*cosh(x)^4 + 4*(a + 3*b)*c 
osh(x)*sinh(x)^3 + (a + 3*b)*sinh(x)^4 - 2*(a + 3*b)*cosh(x)^2 + 2*(3*(a + 
 3*b)*cosh(x)^2 - a - 3*b)*sinh(x)^2 + 4*((a + 3*b)*cosh(x)^3 - (a + 3*b)* 
cosh(x))*sinh(x) + a + 3*b)*log(cosh(x) + sinh(x) + 1) + ((a + 3*b)*cosh(x 
)^4 + 4*(a + 3*b)*cosh(x)*sinh(x)^3 + (a + 3*b)*sinh(x)^4 - 2*(a + 3*b)*co 
sh(x)^2 + 2*(3*(a + 3*b)*cosh(x)^2 - a - 3*b)*sinh(x)^2 + 4*((a + 3*b)*cos 
h(x)^3 - (a + 3*b)*cosh(x))*sinh(x) + a + 3*b)*log(cosh(x) + sinh(x) - 1) 
+ 2*(3*(a + b)*cosh(x)^2 + a + b)*sinh(x))/((a^2 + 2*a*b + b^2)*cosh(x)^4 
+ 4*(a^2 + 2*a*b + b^2)*cosh(x)*sinh(x)^3 + (a^2 + 2*a*b + b^2)*sinh(x)^4 
- 2*(a^2 + 2*a*b + b^2)*cosh(x)^2 + 2*(3*(a^2 + 2*a*b + b^2)*cosh(x)^2 - a 
^2 - 2*a*b - b^2)*sinh(x)^2 + a^2 + 2*a*b + b^2 + 4*((a^2 + 2*a*b + b^2...
 

Sympy [F]

\[ \int \frac {\text {csch}^3(x)}{a+b \cosh ^2(x)} \, dx=\int \frac {\operatorname {csch}^{3}{\left (x \right )}}{a + b \cosh ^{2}{\left (x \right )}}\, dx \] Input:

integrate(csch(x)**3/(a+b*cosh(x)**2),x)
 

Output:

Integral(csch(x)**3/(a + b*cosh(x)**2), x)
 

Maxima [F]

\[ \int \frac {\text {csch}^3(x)}{a+b \cosh ^2(x)} \, dx=\int { \frac {\operatorname {csch}\left (x\right )^{3}}{b \cosh \left (x\right )^{2} + a} \,d x } \] Input:

integrate(csch(x)^3/(a+b*cosh(x)^2),x, algorithm="maxima")
 

Output:

1/2*(a + 3*b)*log(e^x + 1)/(a^2 + 2*a*b + b^2) - 1/2*(a + 3*b)*log(e^x - 1 
)/(a^2 + 2*a*b + b^2) - (e^(3*x) + e^x)/((a + b)*e^(4*x) - 2*(a + b)*e^(2* 
x) + a + b) + 8*integrate(1/4*(b^2*e^(3*x) - b^2*e^x)/(a^2*b + 2*a*b^2 + b 
^3 + (a^2*b + 2*a*b^2 + b^3)*e^(4*x) + 2*(2*a^3 + 5*a^2*b + 4*a*b^2 + b^3) 
*e^(2*x)), x)
 

Giac [F(-2)]

Exception generated. \[ \int \frac {\text {csch}^3(x)}{a+b \cosh ^2(x)} \, dx=\text {Exception raised: TypeError} \] Input:

integrate(csch(x)^3/(a+b*cosh(x)^2),x, algorithm="giac")
 

Output:

Exception raised: TypeError >> an error occurred running a Giac command:IN 
PUT:sage2:=int(sage0,sageVARx):;OUTPUT:Limit: Max order reached or unable 
to make series expansion Error: Bad Argument Value
 

Mupad [B] (verification not implemented)

Time = 8.96 (sec) , antiderivative size = 2225, normalized size of antiderivative = 36.48 \[ \int \frac {\text {csch}^3(x)}{a+b \cosh ^2(x)} \, dx=\text {Too large to display} \] Input:

int(1/(sinh(x)^3*(a + b*cosh(x)^2)),x)
 

Output:

((2*atan((b^2*exp(x)*(a*(a + b)^4)^(1/2))/(2*a*(a + b)^2*(b^3)^(1/2))) - 2 
*atan((exp(x)*((32*(b^8*(a*b^4 + 4*a^4*b + a^5 + 4*a^2*b^3 + 6*a^3*b^2)^(1 
/2) + 36*a^2*b^6*(a*b^4 + 4*a^4*b + a^5 + 4*a^2*b^3 + 6*a^3*b^2)^(1/2) + 4 
7*a^3*b^5*(a*b^4 + 4*a^4*b + a^5 + 4*a^2*b^3 + 6*a^3*b^2)^(1/2) + 30*a^4*b 
^4*(a*b^4 + 4*a^4*b + a^5 + 4*a^2*b^3 + 6*a^3*b^2)^(1/2) + 9*a^5*b^3*(a*b^ 
4 + 4*a^4*b + a^5 + 4*a^2*b^3 + 6*a^3*b^2)^(1/2) + a^6*b^2*(a*b^4 + 4*a^4* 
b + a^5 + 4*a^2*b^3 + 6*a^3*b^2)^(1/2) + 12*a*b^7*(a*b^4 + 4*a^4*b + a^5 + 
 4*a^2*b^3 + 6*a^3*b^2)^(1/2)))/(a^2*b^2*(a + b)^7*(a*b + a^2)*(b^3)^(1/2) 
*(2*a*b + a^2 + b^2)*(3*a*b^2 + 3*a^2*b + a^3 + b^3)*(9*a*b^2 + 6*a^2*b + 
a^3 + b^3)*(a*b^4 + 4*a^4*b + a^5 + 4*a^2*b^3 + 6*a^3*b^2)^(1/2)) + (64*(2 
0*a^3*(b^3)^(5/2) + 232*a^6*(b^3)^(3/2) + 2*a^9*(b^3)^(1/2) + 10*a^2*b^4*( 
b^3)^(3/2) + 20*a^4*b^2*(b^3)^(3/2) + 18*a^2*b^7*(b^3)^(1/2) + 102*a^3*b^6 
*(b^3)^(1/2) + 242*a^4*b^5*(b^3)^(1/2) + 310*a^5*b^4*(b^3)^(1/2) + 98*a^7* 
b^2*(b^3)^(1/2) + 2*a*b^5*(b^3)^(3/2) + 10*a^5*b*(b^3)^(3/2) + 22*a^8*b*(b 
^3)^(1/2)))/(a*b^4*(a + b)^5*(a*b + a^2)*(a*(a + b)^4)^(1/2)*(2*a*b + a^2 
+ b^2)*(3*a*b^2 + 3*a^2*b + a^3 + b^3)*(9*a*b^2 + 6*a^2*b + a^3 + b^3)*(a* 
b^4 + 4*a^4*b + a^5 + 4*a^2*b^3 + 6*a^3*b^2)^(1/2))) + (32*exp(3*x)*(b^8*( 
a*b^4 + 4*a^4*b + a^5 + 4*a^2*b^3 + 6*a^3*b^2)^(1/2) + 36*a^2*b^6*(a*b^4 + 
 4*a^4*b + a^5 + 4*a^2*b^3 + 6*a^3*b^2)^(1/2) + 47*a^3*b^5*(a*b^4 + 4*a^4* 
b + a^5 + 4*a^2*b^3 + 6*a^3*b^2)^(1/2) + 30*a^4*b^4*(a*b^4 + 4*a^4*b + ...
 

Reduce [B] (verification not implemented)

Time = 0.36 (sec) , antiderivative size = 1196, normalized size of antiderivative = 19.61 \[ \int \frac {\text {csch}^3(x)}{a+b \cosh ^2(x)} \, dx =\text {Too large to display} \] Input:

int(csch(x)^3/(a+b*cosh(x)^2),x)
 

Output:

(2*e**(4*x)*sqrt(b)*sqrt(a)*sqrt(a + b)*sqrt(2*sqrt(a)*sqrt(a + b) + 2*a + 
 b)*atan((e**x*b)/(sqrt(b)*sqrt(2*sqrt(a)*sqrt(a + b) + 2*a + b))) - 4*e** 
(2*x)*sqrt(b)*sqrt(a)*sqrt(a + b)*sqrt(2*sqrt(a)*sqrt(a + b) + 2*a + b)*at 
an((e**x*b)/(sqrt(b)*sqrt(2*sqrt(a)*sqrt(a + b) + 2*a + b))) + 2*sqrt(b)*s 
qrt(a)*sqrt(a + b)*sqrt(2*sqrt(a)*sqrt(a + b) + 2*a + b)*atan((e**x*b)/(sq 
rt(b)*sqrt(2*sqrt(a)*sqrt(a + b) + 2*a + b))) - 2*e**(4*x)*sqrt(b)*sqrt(2* 
sqrt(a)*sqrt(a + b) + 2*a + b)*atan((e**x*b)/(sqrt(b)*sqrt(2*sqrt(a)*sqrt( 
a + b) + 2*a + b)))*a + 4*e**(2*x)*sqrt(b)*sqrt(2*sqrt(a)*sqrt(a + b) + 2* 
a + b)*atan((e**x*b)/(sqrt(b)*sqrt(2*sqrt(a)*sqrt(a + b) + 2*a + b)))*a - 
2*sqrt(b)*sqrt(2*sqrt(a)*sqrt(a + b) + 2*a + b)*atan((e**x*b)/(sqrt(b)*sqr 
t(2*sqrt(a)*sqrt(a + b) + 2*a + b)))*a + e**(4*x)*sqrt(b)*sqrt(a)*sqrt(a + 
 b)*sqrt(2*sqrt(a)*sqrt(a + b) - 2*a - b)*log( - sqrt(2*sqrt(a)*sqrt(a + b 
) - 2*a - b) + e**x*sqrt(b)) - e**(4*x)*sqrt(b)*sqrt(a)*sqrt(a + b)*sqrt(2 
*sqrt(a)*sqrt(a + b) - 2*a - b)*log(sqrt(2*sqrt(a)*sqrt(a + b) - 2*a - b) 
+ e**x*sqrt(b)) - 2*e**(2*x)*sqrt(b)*sqrt(a)*sqrt(a + b)*sqrt(2*sqrt(a)*sq 
rt(a + b) - 2*a - b)*log( - sqrt(2*sqrt(a)*sqrt(a + b) - 2*a - b) + e**x*s 
qrt(b)) + 2*e**(2*x)*sqrt(b)*sqrt(a)*sqrt(a + b)*sqrt(2*sqrt(a)*sqrt(a + b 
) - 2*a - b)*log(sqrt(2*sqrt(a)*sqrt(a + b) - 2*a - b) + e**x*sqrt(b)) + s 
qrt(b)*sqrt(a)*sqrt(a + b)*sqrt(2*sqrt(a)*sqrt(a + b) - 2*a - b)*log( - sq 
rt(2*sqrt(a)*sqrt(a + b) - 2*a - b) + e**x*sqrt(b)) - sqrt(b)*sqrt(a)*s...