3.2.48 \(\int \frac {\tanh ^2(c+d x)}{(a+b \text {sech}(c+d x))^{3/2}} \, dx\) [148]

3.2.48.1 Optimal result
3.2.48.2 Mathematica [F]
3.2.48.3 Rubi [A] (verified)
3.2.48.4 Maple [F]
3.2.48.5 Fricas [F]
3.2.48.6 Sympy [F]
3.2.48.7 Maxima [F]
3.2.48.8 Giac [F]
3.2.48.9 Mupad [F(-1)]

3.2.48.1 Optimal result

Integrand size = 23, antiderivative size = 344 \[ \int \frac {\tanh ^2(c+d x)}{(a+b \text {sech}(c+d x))^{3/2}} \, dx=\frac {2 (a-b) \sqrt {a+b} \coth (c+d x) E\left (\arcsin \left (\frac {\sqrt {a+b \text {sech}(c+d x)}}{\sqrt {a+b}}\right )|\frac {a+b}{a-b}\right ) \sqrt {\frac {b (1-\text {sech}(c+d x))}{a+b}} \sqrt {-\frac {b (1+\text {sech}(c+d x))}{a-b}}}{a b^2 d}+\frac {2 \sqrt {a+b} \coth (c+d x) \operatorname {EllipticF}\left (\arcsin \left (\frac {\sqrt {a+b \text {sech}(c+d x)}}{\sqrt {a+b}}\right ),\frac {a+b}{a-b}\right ) \sqrt {\frac {b (1-\text {sech}(c+d x))}{a+b}} \sqrt {-\frac {b (1+\text {sech}(c+d x))}{a-b}}}{a b d}+\frac {2 \sqrt {a+b} \coth (c+d x) \operatorname {EllipticPi}\left (\frac {a+b}{a},\arcsin \left (\frac {\sqrt {a+b \text {sech}(c+d x)}}{\sqrt {a+b}}\right ),\frac {a+b}{a-b}\right ) \sqrt {\frac {b (1-\text {sech}(c+d x))}{a+b}} \sqrt {-\frac {b (1+\text {sech}(c+d x))}{a-b}}}{a^2 d}-\frac {2 \tanh (c+d x)}{a d \sqrt {a+b \text {sech}(c+d x)}} \]

output
2*(a-b)*coth(d*x+c)*EllipticE((a+b*sech(d*x+c))^(1/2)/(a+b)^(1/2),((a+b)/( 
a-b))^(1/2))*(a+b)^(1/2)*(b*(1-sech(d*x+c))/(a+b))^(1/2)*(-b*(1+sech(d*x+c 
))/(a-b))^(1/2)/a/b^2/d+2*coth(d*x+c)*EllipticF((a+b*sech(d*x+c))^(1/2)/(a 
+b)^(1/2),((a+b)/(a-b))^(1/2))*(a+b)^(1/2)*(b*(1-sech(d*x+c))/(a+b))^(1/2) 
*(-b*(1+sech(d*x+c))/(a-b))^(1/2)/a/b/d+2*coth(d*x+c)*EllipticPi((a+b*sech 
(d*x+c))^(1/2)/(a+b)^(1/2),(a+b)/a,((a+b)/(a-b))^(1/2))*(a+b)^(1/2)*(b*(1- 
sech(d*x+c))/(a+b))^(1/2)*(-b*(1+sech(d*x+c))/(a-b))^(1/2)/a^2/d-2*tanh(d* 
x+c)/a/d/(a+b*sech(d*x+c))^(1/2)
 
3.2.48.2 Mathematica [F]

\[ \int \frac {\tanh ^2(c+d x)}{(a+b \text {sech}(c+d x))^{3/2}} \, dx=\int \frac {\tanh ^2(c+d x)}{(a+b \text {sech}(c+d x))^{3/2}} \, dx \]

input
Integrate[Tanh[c + d*x]^2/(a + b*Sech[c + d*x])^(3/2),x]
 
output
Integrate[Tanh[c + d*x]^2/(a + b*Sech[c + d*x])^(3/2), x]
 
3.2.48.3 Rubi [A] (verified)

Time = 1.49 (sec) , antiderivative size = 381, normalized size of antiderivative = 1.11, number of steps used = 14, number of rules used = 14, \(\frac {\text {number of rules}}{\text {integrand size}}\) = 0.609, Rules used = {3042, 25, 4382, 3042, 4549, 27, 3042, 4547, 3042, 4409, 3042, 4271, 4319, 4492}

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.

\(\displaystyle \int \frac {\tanh ^2(c+d x)}{(a+b \text {sech}(c+d x))^{3/2}} \, dx\)

\(\Big \downarrow \) 3042

\(\displaystyle \int -\frac {\cot \left (i c+i d x+\frac {\pi }{2}\right )^2}{\left (a+b \csc \left (i c+i d x+\frac {\pi }{2}\right )\right )^{3/2}}dx\)

\(\Big \downarrow \) 25

\(\displaystyle -\int \frac {\cot \left (\frac {1}{2} (2 i c+\pi )+i d x\right )^2}{\left (a+b \csc \left (\frac {1}{2} (2 i c+\pi )+i d x\right )\right )^{3/2}}dx\)

\(\Big \downarrow \) 4382

\(\displaystyle -\int \frac {\csc ^2\left (\frac {1}{2} (2 i c+\pi )+i d x\right )-1}{\left (a+b \csc \left (\frac {1}{2} (2 i c+\pi )+i d x\right )\right )^{3/2}}dx\)

\(\Big \downarrow \) 3042

\(\displaystyle -\int \frac {\csc \left (i c+i d x+\frac {\pi }{2}\right )^2-1}{\left (a+b \csc \left (i c+i d x+\frac {\pi }{2}\right )\right )^{3/2}}dx\)

\(\Big \downarrow \) 4549

\(\displaystyle \frac {2 \int \frac {a^2-b^2+\left (a^2-b^2\right ) \text {sech}^2(c+d x)}{2 \sqrt {a+b \text {sech}(c+d x)}}dx}{a \left (a^2-b^2\right )}-\frac {2 \tanh (c+d x)}{a d \sqrt {a+b \text {sech}(c+d x)}}\)

\(\Big \downarrow \) 27

\(\displaystyle \frac {\int \frac {a^2-b^2+\left (a^2-b^2\right ) \text {sech}^2(c+d x)}{\sqrt {a+b \text {sech}(c+d x)}}dx}{a \left (a^2-b^2\right )}-\frac {2 \tanh (c+d x)}{a d \sqrt {a+b \text {sech}(c+d x)}}\)

\(\Big \downarrow \) 3042

\(\displaystyle -\frac {2 \tanh (c+d x)}{a d \sqrt {a+b \text {sech}(c+d x)}}+\frac {\int \frac {a^2-b^2+\left (a^2-b^2\right ) \csc \left (i c+i d x+\frac {\pi }{2}\right )^2}{\sqrt {a+b \csc \left (i c+i d x+\frac {\pi }{2}\right )}}dx}{a \left (a^2-b^2\right )}\)

\(\Big \downarrow \) 4547

\(\displaystyle \frac {\left (a^2-b^2\right ) \int \frac {\text {sech}(c+d x) (\text {sech}(c+d x)+1)}{\sqrt {a+b \text {sech}(c+d x)}}dx+\int \frac {a^2-b^2-\left (a^2-b^2\right ) \text {sech}(c+d x)}{\sqrt {a+b \text {sech}(c+d x)}}dx}{a \left (a^2-b^2\right )}-\frac {2 \tanh (c+d x)}{a d \sqrt {a+b \text {sech}(c+d x)}}\)

\(\Big \downarrow \) 3042

\(\displaystyle -\frac {2 \tanh (c+d x)}{a d \sqrt {a+b \text {sech}(c+d x)}}+\frac {\left (a^2-b^2\right ) \int \frac {\csc \left (i c+i d x+\frac {\pi }{2}\right ) \left (\csc \left (i c+i d x+\frac {\pi }{2}\right )+1\right )}{\sqrt {a+b \csc \left (i c+i d x+\frac {\pi }{2}\right )}}dx+\int \frac {a^2-b^2+\left (b^2-a^2\right ) \csc \left (i c+i d x+\frac {\pi }{2}\right )}{\sqrt {a+b \csc \left (i c+i d x+\frac {\pi }{2}\right )}}dx}{a \left (a^2-b^2\right )}\)

\(\Big \downarrow \) 4409

\(\displaystyle -\frac {2 \tanh (c+d x)}{a d \sqrt {a+b \text {sech}(c+d x)}}+\frac {\left (a^2-b^2\right ) \int \frac {\csc \left (i c+i d x+\frac {\pi }{2}\right ) \left (\csc \left (i c+i d x+\frac {\pi }{2}\right )+1\right )}{\sqrt {a+b \csc \left (i c+i d x+\frac {\pi }{2}\right )}}dx+\left (a^2-b^2\right ) \int \frac {1}{\sqrt {a+b \text {sech}(c+d x)}}dx-\left (a^2-b^2\right ) \int \frac {\text {sech}(c+d x)}{\sqrt {a+b \text {sech}(c+d x)}}dx}{a \left (a^2-b^2\right )}\)

\(\Big \downarrow \) 3042

\(\displaystyle -\frac {2 \tanh (c+d x)}{a d \sqrt {a+b \text {sech}(c+d x)}}+\frac {\left (a^2-b^2\right ) \int \frac {1}{\sqrt {a+b \csc \left (i c+i d x+\frac {\pi }{2}\right )}}dx-\left (a^2-b^2\right ) \int \frac {\csc \left (i c+i d x+\frac {\pi }{2}\right )}{\sqrt {a+b \csc \left (i c+i d x+\frac {\pi }{2}\right )}}dx+\left (a^2-b^2\right ) \int \frac {\csc \left (i c+i d x+\frac {\pi }{2}\right ) \left (\csc \left (i c+i d x+\frac {\pi }{2}\right )+1\right )}{\sqrt {a+b \csc \left (i c+i d x+\frac {\pi }{2}\right )}}dx}{a \left (a^2-b^2\right )}\)

\(\Big \downarrow \) 4271

\(\displaystyle -\frac {2 \tanh (c+d x)}{a d \sqrt {a+b \text {sech}(c+d x)}}+\frac {-\left (a^2-b^2\right ) \int \frac {\csc \left (i c+i d x+\frac {\pi }{2}\right )}{\sqrt {a+b \csc \left (i c+i d x+\frac {\pi }{2}\right )}}dx+\left (a^2-b^2\right ) \int \frac {\csc \left (i c+i d x+\frac {\pi }{2}\right ) \left (\csc \left (i c+i d x+\frac {\pi }{2}\right )+1\right )}{\sqrt {a+b \csc \left (i c+i d x+\frac {\pi }{2}\right )}}dx+\frac {2 \sqrt {a+b} \left (a^2-b^2\right ) \coth (c+d x) \sqrt {\frac {b (1-\text {sech}(c+d x))}{a+b}} \sqrt {-\frac {b (\text {sech}(c+d x)+1)}{a-b}} \operatorname {EllipticPi}\left (\frac {a+b}{a},\arcsin \left (\frac {\sqrt {a+b \text {sech}(c+d x)}}{\sqrt {a+b}}\right ),\frac {a+b}{a-b}\right )}{a d}}{a \left (a^2-b^2\right )}\)

\(\Big \downarrow \) 4319

\(\displaystyle -\frac {2 \tanh (c+d x)}{a d \sqrt {a+b \text {sech}(c+d x)}}+\frac {\left (a^2-b^2\right ) \int \frac {\csc \left (i c+i d x+\frac {\pi }{2}\right ) \left (\csc \left (i c+i d x+\frac {\pi }{2}\right )+1\right )}{\sqrt {a+b \csc \left (i c+i d x+\frac {\pi }{2}\right )}}dx+\frac {2 \sqrt {a+b} \left (a^2-b^2\right ) \coth (c+d x) \sqrt {\frac {b (1-\text {sech}(c+d x))}{a+b}} \sqrt {-\frac {b (\text {sech}(c+d x)+1)}{a-b}} \operatorname {EllipticF}\left (\arcsin \left (\frac {\sqrt {a+b \text {sech}(c+d x)}}{\sqrt {a+b}}\right ),\frac {a+b}{a-b}\right )}{b d}+\frac {2 \sqrt {a+b} \left (a^2-b^2\right ) \coth (c+d x) \sqrt {\frac {b (1-\text {sech}(c+d x))}{a+b}} \sqrt {-\frac {b (\text {sech}(c+d x)+1)}{a-b}} \operatorname {EllipticPi}\left (\frac {a+b}{a},\arcsin \left (\frac {\sqrt {a+b \text {sech}(c+d x)}}{\sqrt {a+b}}\right ),\frac {a+b}{a-b}\right )}{a d}}{a \left (a^2-b^2\right )}\)

\(\Big \downarrow \) 4492

\(\displaystyle \frac {\frac {2 \sqrt {a+b} \left (a^2-b^2\right ) \coth (c+d x) \sqrt {\frac {b (1-\text {sech}(c+d x))}{a+b}} \sqrt {-\frac {b (\text {sech}(c+d x)+1)}{a-b}} \operatorname {EllipticF}\left (\arcsin \left (\frac {\sqrt {a+b \text {sech}(c+d x)}}{\sqrt {a+b}}\right ),\frac {a+b}{a-b}\right )}{b d}+\frac {2 (a-b) \sqrt {a+b} \left (a^2-b^2\right ) \coth (c+d x) \sqrt {\frac {b (1-\text {sech}(c+d x))}{a+b}} \sqrt {-\frac {b (\text {sech}(c+d x)+1)}{a-b}} E\left (\arcsin \left (\frac {\sqrt {a+b \text {sech}(c+d x)}}{\sqrt {a+b}}\right )|\frac {a+b}{a-b}\right )}{b^2 d}+\frac {2 \sqrt {a+b} \left (a^2-b^2\right ) \coth (c+d x) \sqrt {\frac {b (1-\text {sech}(c+d x))}{a+b}} \sqrt {-\frac {b (\text {sech}(c+d x)+1)}{a-b}} \operatorname {EllipticPi}\left (\frac {a+b}{a},\arcsin \left (\frac {\sqrt {a+b \text {sech}(c+d x)}}{\sqrt {a+b}}\right ),\frac {a+b}{a-b}\right )}{a d}}{a \left (a^2-b^2\right )}-\frac {2 \tanh (c+d x)}{a d \sqrt {a+b \text {sech}(c+d x)}}\)

input
Int[Tanh[c + d*x]^2/(a + b*Sech[c + d*x])^(3/2),x]
 
output
((2*(a - b)*Sqrt[a + b]*(a^2 - b^2)*Coth[c + d*x]*EllipticE[ArcSin[Sqrt[a 
+ b*Sech[c + d*x]]/Sqrt[a + b]], (a + b)/(a - b)]*Sqrt[(b*(1 - Sech[c + d* 
x]))/(a + b)]*Sqrt[-((b*(1 + Sech[c + d*x]))/(a - b))])/(b^2*d) + (2*Sqrt[ 
a + b]*(a^2 - b^2)*Coth[c + d*x]*EllipticF[ArcSin[Sqrt[a + b*Sech[c + d*x] 
]/Sqrt[a + b]], (a + b)/(a - b)]*Sqrt[(b*(1 - Sech[c + d*x]))/(a + b)]*Sqr 
t[-((b*(1 + Sech[c + d*x]))/(a - b))])/(b*d) + (2*Sqrt[a + b]*(a^2 - b^2)* 
Coth[c + d*x]*EllipticPi[(a + b)/a, ArcSin[Sqrt[a + b*Sech[c + d*x]]/Sqrt[ 
a + b]], (a + b)/(a - b)]*Sqrt[(b*(1 - Sech[c + d*x]))/(a + b)]*Sqrt[-((b* 
(1 + Sech[c + d*x]))/(a - b))])/(a*d))/(a*(a^2 - b^2)) - (2*Tanh[c + d*x]) 
/(a*d*Sqrt[a + b*Sech[c + d*x]])
 

3.2.48.3.1 Defintions of rubi rules used

rule 25
Int[-(Fx_), x_Symbol] :> Simp[Identity[-1]   Int[Fx, x], x]
 

rule 27
Int[(a_)*(Fx_), x_Symbol] :> Simp[a   Int[Fx, x], x] /; FreeQ[a, x] &&  !Ma 
tchQ[Fx, (b_)*(Gx_) /; FreeQ[b, x]]
 

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

rule 4271
Int[1/Sqrt[csc[(c_.) + (d_.)*(x_)]*(b_.) + (a_)], x_Symbol] :> Simp[2*(Rt[a 
 + b, 2]/(a*d*Cot[c + d*x]))*Sqrt[b*((1 - Csc[c + d*x])/(a + b))]*Sqrt[(-b) 
*((1 + Csc[c + d*x])/(a - b))]*EllipticPi[(a + b)/a, ArcSin[Sqrt[a + b*Csc[ 
c + d*x]]/Rt[a + b, 2]], (a + b)/(a - b)], x] /; FreeQ[{a, b, c, d}, x] && 
NeQ[a^2 - b^2, 0]
 

rule 4319
Int[csc[(e_.) + (f_.)*(x_)]/Sqrt[csc[(e_.) + (f_.)*(x_)]*(b_.) + (a_)], x_S 
ymbol] :> Simp[-2*(Rt[a + b, 2]/(b*f*Cot[e + f*x]))*Sqrt[(b*(1 - Csc[e + f* 
x]))/(a + b)]*Sqrt[(-b)*((1 + Csc[e + f*x])/(a - b))]*EllipticF[ArcSin[Sqrt 
[a + b*Csc[e + f*x]]/Rt[a + b, 2]], (a + b)/(a - b)], x] /; FreeQ[{a, b, e, 
 f}, x] && NeQ[a^2 - b^2, 0]
 

rule 4382
Int[cot[(c_.) + (d_.)*(x_)]^2*(csc[(c_.) + (d_.)*(x_)]*(b_.) + (a_))^(n_), 
x_Symbol] :> Int[(-1 + Csc[c + d*x]^2)*(a + b*Csc[c + d*x])^n, x] /; FreeQ[ 
{a, b, c, d, n}, x] && NeQ[a^2 - b^2, 0]
 

rule 4409
Int[(csc[(e_.) + (f_.)*(x_)]*(d_.) + (c_))/Sqrt[csc[(e_.) + (f_.)*(x_)]*(b_ 
.) + (a_)], x_Symbol] :> Simp[c   Int[1/Sqrt[a + b*Csc[e + f*x]], x], x] + 
Simp[d   Int[Csc[e + f*x]/Sqrt[a + b*Csc[e + f*x]], x], x] /; FreeQ[{a, b, 
c, d, e, f}, x] && NeQ[b*c - a*d, 0] && NeQ[a^2 - b^2, 0]
 

rule 4492
Int[(csc[(e_.) + (f_.)*(x_)]*(csc[(e_.) + (f_.)*(x_)]*(B_.) + (A_)))/Sqrt[c 
sc[(e_.) + (f_.)*(x_)]*(b_.) + (a_)], x_Symbol] :> Simp[-2*(A*b - a*B)*Rt[a 
 + b*(B/A), 2]*Sqrt[b*((1 - Csc[e + f*x])/(a + b))]*(Sqrt[(-b)*((1 + Csc[e 
+ f*x])/(a - b))]/(b^2*f*Cot[e + f*x]))*EllipticE[ArcSin[Sqrt[a + b*Csc[e + 
 f*x]]/Rt[a + b*(B/A), 2]], (a*A + b*B)/(a*A - b*B)], x] /; FreeQ[{a, b, e, 
 f, A, B}, x] && NeQ[a^2 - b^2, 0] && EqQ[A^2 - B^2, 0]
 

rule 4547
Int[((A_.) + csc[(e_.) + (f_.)*(x_)]^2*(C_.))/Sqrt[csc[(e_.) + (f_.)*(x_)]* 
(b_.) + (a_)], x_Symbol] :> Int[(A - C*Csc[e + f*x])/Sqrt[a + b*Csc[e + f*x 
]], x] + Simp[C   Int[Csc[e + f*x]*((1 + Csc[e + f*x])/Sqrt[a + b*Csc[e + f 
*x]]), x], x] /; FreeQ[{a, b, e, f, A, C}, x] && NeQ[a^2 - b^2, 0]
 

rule 4549
Int[((A_.) + csc[(e_.) + (f_.)*(x_)]^2*(C_.))*(csc[(e_.) + (f_.)*(x_)]*(b_. 
) + (a_))^(m_), x_Symbol] :> Simp[(A*b^2 + a^2*C)*Cot[e + f*x]*((a + b*Csc[ 
e + f*x])^(m + 1)/(a*f*(m + 1)*(a^2 - b^2))), x] + Simp[1/(a*(m + 1)*(a^2 - 
 b^2))   Int[(a + b*Csc[e + f*x])^(m + 1)*Simp[A*(a^2 - b^2)*(m + 1) - a*b* 
(A + C)*(m + 1)*Csc[e + f*x] + (A*b^2 + a^2*C)*(m + 2)*Csc[e + f*x]^2, x], 
x], x] /; FreeQ[{a, b, e, f, A, C}, x] && NeQ[a^2 - b^2, 0] && IntegerQ[2*m 
] && LtQ[m, -1]
 
3.2.48.4 Maple [F]

\[\int \frac {\tanh \left (d x +c \right )^{2}}{\left (a +b \,\operatorname {sech}\left (d x +c \right )\right )^{\frac {3}{2}}}d x\]

input
int(tanh(d*x+c)^2/(a+b*sech(d*x+c))^(3/2),x)
 
output
int(tanh(d*x+c)^2/(a+b*sech(d*x+c))^(3/2),x)
 
3.2.48.5 Fricas [F]

\[ \int \frac {\tanh ^2(c+d x)}{(a+b \text {sech}(c+d x))^{3/2}} \, dx=\int { \frac {\tanh \left (d x + c\right )^{2}}{{\left (b \operatorname {sech}\left (d x + c\right ) + a\right )}^{\frac {3}{2}}} \,d x } \]

input
integrate(tanh(d*x+c)^2/(a+b*sech(d*x+c))^(3/2),x, algorithm="fricas")
 
output
integral(sqrt(b*sech(d*x + c) + a)*tanh(d*x + c)^2/(b^2*sech(d*x + c)^2 + 
2*a*b*sech(d*x + c) + a^2), x)
 
3.2.48.6 Sympy [F]

\[ \int \frac {\tanh ^2(c+d x)}{(a+b \text {sech}(c+d x))^{3/2}} \, dx=\int \frac {\tanh ^{2}{\left (c + d x \right )}}{\left (a + b \operatorname {sech}{\left (c + d x \right )}\right )^{\frac {3}{2}}}\, dx \]

input
integrate(tanh(d*x+c)**2/(a+b*sech(d*x+c))**(3/2),x)
 
output
Integral(tanh(c + d*x)**2/(a + b*sech(c + d*x))**(3/2), x)
 
3.2.48.7 Maxima [F]

\[ \int \frac {\tanh ^2(c+d x)}{(a+b \text {sech}(c+d x))^{3/2}} \, dx=\int { \frac {\tanh \left (d x + c\right )^{2}}{{\left (b \operatorname {sech}\left (d x + c\right ) + a\right )}^{\frac {3}{2}}} \,d x } \]

input
integrate(tanh(d*x+c)^2/(a+b*sech(d*x+c))^(3/2),x, algorithm="maxima")
 
output
integrate(tanh(d*x + c)^2/(b*sech(d*x + c) + a)^(3/2), x)
 
3.2.48.8 Giac [F]

\[ \int \frac {\tanh ^2(c+d x)}{(a+b \text {sech}(c+d x))^{3/2}} \, dx=\int { \frac {\tanh \left (d x + c\right )^{2}}{{\left (b \operatorname {sech}\left (d x + c\right ) + a\right )}^{\frac {3}{2}}} \,d x } \]

input
integrate(tanh(d*x+c)^2/(a+b*sech(d*x+c))^(3/2),x, algorithm="giac")
 
output
integrate(tanh(d*x + c)^2/(b*sech(d*x + c) + a)^(3/2), x)
 
3.2.48.9 Mupad [F(-1)]

Timed out. \[ \int \frac {\tanh ^2(c+d x)}{(a+b \text {sech}(c+d x))^{3/2}} \, dx=\int \frac {{\mathrm {tanh}\left (c+d\,x\right )}^2}{{\left (a+\frac {b}{\mathrm {cosh}\left (c+d\,x\right )}\right )}^{3/2}} \,d x \]

input
int(tanh(c + d*x)^2/(a + b/cosh(c + d*x))^(3/2),x)
 
output
int(tanh(c + d*x)^2/(a + b/cosh(c + d*x))^(3/2), x)