Integrand size = 12, antiderivative size = 119 \[ \int (c+d x) \text {erfc}(a+b x) \, dx=-\frac {(b c-a d) e^{-(a+b x)^2}}{b^2 \sqrt {\pi }}-\frac {d e^{-(a+b x)^2} (a+b x)}{2 b^2 \sqrt {\pi }}+\frac {d \text {erf}(a+b x)}{4 b^2}+\frac {(b c-a d)^2 \text {erf}(a+b x)}{2 b^2 d}+\frac {(c+d x)^2 \text {erfc}(a+b x)}{2 d} \]
1/4*d*erf(b*x+a)/b^2+1/2*(-a*d+b*c)^2*erf(b*x+a)/b^2/d+1/2*(d*x+c)^2*erfc( b*x+a)/d+(a*d-b*c)/b^2/exp((b*x+a)^2)/Pi^(1/2)-1/2*d*(b*x+a)/b^2/exp((b*x+ a)^2)/Pi^(1/2)
Time = 0.09 (sec) , antiderivative size = 104, normalized size of antiderivative = 0.87 \[ \int (c+d x) \text {erfc}(a+b x) \, dx=\frac {e^{-(a+b x)^2} \left (-4 b c+2 a d-2 b d x+\left (-4 a b c+d+2 a^2 d\right ) e^{(a+b x)^2} \sqrt {\pi } \text {erf}(a+b x)+2 b^2 e^{(a+b x)^2} \sqrt {\pi } x (2 c+d x) \text {erfc}(a+b x)\right )}{4 b^2 \sqrt {\pi }} \]
(-4*b*c + 2*a*d - 2*b*d*x + (-4*a*b*c + d + 2*a^2*d)*E^(a + b*x)^2*Sqrt[Pi ]*Erf[a + b*x] + 2*b^2*E^(a + b*x)^2*Sqrt[Pi]*x*(2*c + d*x)*Erfc[a + b*x]) /(4*b^2*E^(a + b*x)^2*Sqrt[Pi])
Time = 0.35 (sec) , antiderivative size = 132, normalized size of antiderivative = 1.11, number of steps used = 3, number of rules used = 3, \(\frac {\text {number of rules}}{\text {integrand size}}\) = 0.250, Rules used = {6916, 2656, 2009}
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.
\(\displaystyle \int (c+d x) \text {erfc}(a+b x) \, dx\) |
\(\Big \downarrow \) 6916 |
\(\displaystyle \frac {b \int e^{-(a+b x)^2} (c+d x)^2dx}{\sqrt {\pi } d}+\frac {(c+d x)^2 \text {erfc}(a+b x)}{2 d}\) |
\(\Big \downarrow \) 2656 |
\(\displaystyle \frac {b \int \left (\frac {e^{-(a+b x)^2} (b c-a d)^2}{b^2}+\frac {2 d e^{-(a+b x)^2} (a+b x) (b c-a d)}{b^2}+\frac {d^2 e^{-(a+b x)^2} (a+b x)^2}{b^2}\right )dx}{\sqrt {\pi } d}+\frac {(c+d x)^2 \text {erfc}(a+b x)}{2 d}\) |
\(\Big \downarrow \) 2009 |
\(\displaystyle \frac {b \left (\frac {\sqrt {\pi } (b c-a d)^2 \text {erf}(a+b x)}{2 b^3}-\frac {d e^{-(a+b x)^2} (b c-a d)}{b^3}+\frac {\sqrt {\pi } d^2 \text {erf}(a+b x)}{4 b^3}-\frac {d^2 e^{-(a+b x)^2} (a+b x)}{2 b^3}\right )}{\sqrt {\pi } d}+\frac {(c+d x)^2 \text {erfc}(a+b x)}{2 d}\) |
(b*(-((d*(b*c - a*d))/(b^3*E^(a + b*x)^2)) - (d^2*(a + b*x))/(2*b^3*E^(a + b*x)^2) + (d^2*Sqrt[Pi]*Erf[a + b*x])/(4*b^3) + ((b*c - a*d)^2*Sqrt[Pi]*E rf[a + b*x])/(2*b^3)))/(d*Sqrt[Pi]) + ((c + d*x)^2*Erfc[a + b*x])/(2*d)
3.2.20.3.1 Defintions of rubi rules used
Int[(F_)^((a_.) + (b_.)*((c_.) + (d_.)*(x_))^(n_))*(Px_), x_Symbol] :> Int[ ExpandLinearProduct[F^(a + b*(c + d*x)^n), Px, c, d, x], x] /; FreeQ[{F, a, b, c, d, n}, x] && PolynomialQ[Px, x]
Int[Erfc[(a_.) + (b_.)*(x_)]*((c_.) + (d_.)*(x_))^(m_.), x_Symbol] :> Simp[ (c + d*x)^(m + 1)*(Erfc[a + b*x]/(d*(m + 1))), x] + Simp[2*(b/(Sqrt[Pi]*d*( m + 1))) Int[(c + d*x)^(m + 1)/E^(a + b*x)^2, x], x] /; FreeQ[{a, b, c, d , m}, x] && NeQ[m, -1]
Time = 0.34 (sec) , antiderivative size = 124, normalized size of antiderivative = 1.04
method | result | size |
derivativedivides | \(\frac {-\frac {\operatorname {erfc}\left (b x +a \right ) d a \left (b x +a \right )}{b}+\operatorname {erfc}\left (b x +a \right ) c \left (b x +a \right )+\frac {\operatorname {erfc}\left (b x +a \right ) d \left (b x +a \right )^{2}}{2 b}-\frac {-d \left (-\frac {\left (b x +a \right ) {\mathrm e}^{-\left (b x +a \right )^{2}}}{2}+\frac {\sqrt {\pi }\, \operatorname {erf}\left (b x +a \right )}{4}\right )+{\mathrm e}^{-\left (b x +a \right )^{2}} b c -{\mathrm e}^{-\left (b x +a \right )^{2}} a d}{\sqrt {\pi }\, b}}{b}\) | \(124\) |
default | \(\frac {-\frac {\operatorname {erfc}\left (b x +a \right ) d a \left (b x +a \right )}{b}+\operatorname {erfc}\left (b x +a \right ) c \left (b x +a \right )+\frac {\operatorname {erfc}\left (b x +a \right ) d \left (b x +a \right )^{2}}{2 b}-\frac {-d \left (-\frac {\left (b x +a \right ) {\mathrm e}^{-\left (b x +a \right )^{2}}}{2}+\frac {\sqrt {\pi }\, \operatorname {erf}\left (b x +a \right )}{4}\right )+{\mathrm e}^{-\left (b x +a \right )^{2}} b c -{\mathrm e}^{-\left (b x +a \right )^{2}} a d}{\sqrt {\pi }\, b}}{b}\) | \(124\) |
parallelrisch | \(\frac {2 d \,x^{2} \operatorname {erfc}\left (b x +a \right ) b^{2} \sqrt {\pi }+4 x \,\operatorname {erfc}\left (b x +a \right ) c \,b^{2} \sqrt {\pi }-2 \sqrt {\pi }\, \operatorname {erfc}\left (b x +a \right ) a^{2} d +4 \sqrt {\pi }\, \operatorname {erfc}\left (b x +a \right ) a b c -2 \,{\mathrm e}^{-\left (b x +a \right )^{2}} b d x -d \,\operatorname {erfc}\left (b x +a \right ) \sqrt {\pi }+2 \,{\mathrm e}^{-\left (b x +a \right )^{2}} a d -4 \,{\mathrm e}^{-\left (b x +a \right )^{2}} b c}{4 b^{2} \sqrt {\pi }}\) | \(128\) |
parts | \(\frac {\operatorname {erfc}\left (b x +a \right ) d \,x^{2}}{2}+\operatorname {erfc}\left (b x +a \right ) c x +\frac {b \left ({\mathrm e}^{-a^{2}} d \left (-\frac {x \,{\mathrm e}^{-b^{2} x^{2}-2 a b x}}{2 b^{2}}-\frac {a \left (-\frac {{\mathrm e}^{-b^{2} x^{2}-2 a b x}}{2 b^{2}}-\frac {a \sqrt {\pi }\, {\mathrm e}^{a^{2}} \operatorname {erf}\left (b x +a \right )}{2 b^{2}}\right )}{b}+\frac {\sqrt {\pi }\, {\mathrm e}^{a^{2}} \operatorname {erf}\left (b x +a \right )}{4 b^{3}}\right )+2 \,{\mathrm e}^{-a^{2}} c \left (-\frac {{\mathrm e}^{-b^{2} x^{2}-2 a b x}}{2 b^{2}}-\frac {a \sqrt {\pi }\, {\mathrm e}^{a^{2}} \operatorname {erf}\left (b x +a \right )}{2 b^{2}}\right )\right )}{\sqrt {\pi }}\) | \(172\) |
1/b*(-1/b*erfc(b*x+a)*d*a*(b*x+a)+erfc(b*x+a)*c*(b*x+a)+1/2/b*erfc(b*x+a)* d*(b*x+a)^2-1/b/Pi^(1/2)*(-d*(-1/2*(b*x+a)/exp((b*x+a)^2)+1/4*Pi^(1/2)*erf (b*x+a))+c*b/exp((b*x+a)^2)-d*a/exp((b*x+a)^2)))
Time = 0.24 (sec) , antiderivative size = 110, normalized size of antiderivative = 0.92 \[ \int (c+d x) \text {erfc}(a+b x) \, dx=\frac {2 \, \pi b^{2} d x^{2} + 4 \, \pi b^{2} c x - 2 \, \sqrt {\pi } {\left (b d x + 2 \, b c - a d\right )} e^{\left (-b^{2} x^{2} - 2 \, a b x - a^{2}\right )} - {\left (2 \, \pi b^{2} d x^{2} + 4 \, \pi b^{2} c x + \pi {\left (4 \, a b c - {\left (2 \, a^{2} + 1\right )} d\right )}\right )} \operatorname {erf}\left (b x + a\right )}{4 \, \pi b^{2}} \]
1/4*(2*pi*b^2*d*x^2 + 4*pi*b^2*c*x - 2*sqrt(pi)*(b*d*x + 2*b*c - a*d)*e^(- b^2*x^2 - 2*a*b*x - a^2) - (2*pi*b^2*d*x^2 + 4*pi*b^2*c*x + pi*(4*a*b*c - (2*a^2 + 1)*d))*erf(b*x + a))/(pi*b^2)
Time = 0.43 (sec) , antiderivative size = 178, normalized size of antiderivative = 1.50 \[ \int (c+d x) \text {erfc}(a+b x) \, dx=\begin {cases} - \frac {a^{2} d \operatorname {erfc}{\left (a + b x \right )}}{2 b^{2}} + \frac {a c \operatorname {erfc}{\left (a + b x \right )}}{b} + \frac {a d e^{- a^{2}} e^{- b^{2} x^{2}} e^{- 2 a b x}}{2 \sqrt {\pi } b^{2}} + c x \operatorname {erfc}{\left (a + b x \right )} + \frac {d x^{2} \operatorname {erfc}{\left (a + b x \right )}}{2} - \frac {c e^{- a^{2}} e^{- b^{2} x^{2}} e^{- 2 a b x}}{\sqrt {\pi } b} - \frac {d x e^{- a^{2}} e^{- b^{2} x^{2}} e^{- 2 a b x}}{2 \sqrt {\pi } b} - \frac {d \operatorname {erfc}{\left (a + b x \right )}}{4 b^{2}} & \text {for}\: b \neq 0 \\\left (c x + \frac {d x^{2}}{2}\right ) \operatorname {erfc}{\left (a \right )} & \text {otherwise} \end {cases} \]
Piecewise((-a**2*d*erfc(a + b*x)/(2*b**2) + a*c*erfc(a + b*x)/b + a*d*exp( -a**2)*exp(-b**2*x**2)*exp(-2*a*b*x)/(2*sqrt(pi)*b**2) + c*x*erfc(a + b*x) + d*x**2*erfc(a + b*x)/2 - c*exp(-a**2)*exp(-b**2*x**2)*exp(-2*a*b*x)/(sq rt(pi)*b) - d*x*exp(-a**2)*exp(-b**2*x**2)*exp(-2*a*b*x)/(2*sqrt(pi)*b) - d*erfc(a + b*x)/(4*b**2), Ne(b, 0)), ((c*x + d*x**2/2)*erfc(a), True))
\[ \int (c+d x) \text {erfc}(a+b x) \, dx=\int { {\left (d x + c\right )} \operatorname {erfc}\left (b x + a\right ) \,d x } \]
Time = 0.35 (sec) , antiderivative size = 158, normalized size of antiderivative = 1.33 \[ \int (c+d x) \text {erfc}(a+b x) \, dx=\frac {1}{2} \, d x^{2} - {\left (x \operatorname {erf}\left (b x + a\right ) - \frac {\frac {\sqrt {\pi } a \operatorname {erf}\left (-b {\left (x + \frac {a}{b}\right )}\right )}{b} - \frac {e^{\left (-b^{2} x^{2} - 2 \, a b x - a^{2}\right )}}{b}}{\sqrt {\pi }}\right )} c - \frac {1}{4} \, {\left (2 \, x^{2} \operatorname {erf}\left (b x + a\right ) + \frac {\frac {\sqrt {\pi } {\left (2 \, a^{2} + 1\right )} \operatorname {erf}\left (-b {\left (x + \frac {a}{b}\right )}\right )}{b} + \frac {2 \, {\left (b {\left (x + \frac {a}{b}\right )} - 2 \, a\right )} e^{\left (-b^{2} x^{2} - 2 \, a b x - a^{2}\right )}}{b}}{\sqrt {\pi } b}\right )} d + c x \]
1/2*d*x^2 - (x*erf(b*x + a) - (sqrt(pi)*a*erf(-b*(x + a/b))/b - e^(-b^2*x^ 2 - 2*a*b*x - a^2)/b)/sqrt(pi))*c - 1/4*(2*x^2*erf(b*x + a) + (sqrt(pi)*(2 *a^2 + 1)*erf(-b*(x + a/b))/b + 2*(b*(x + a/b) - 2*a)*e^(-b^2*x^2 - 2*a*b* x - a^2)/b)/(sqrt(pi)*b))*d + c*x
Time = 5.19 (sec) , antiderivative size = 119, normalized size of antiderivative = 1.00 \[ \int (c+d x) \text {erfc}(a+b x) \, dx=c\,x\,\mathrm {erfc}\left (a+b\,x\right )-{\mathrm {e}}^{-a^2-2\,a\,b\,x-b^2\,x^2}\,\left (\frac {c}{b\,\sqrt {\pi }}-\frac {a\,d}{2\,b^2\,\sqrt {\pi }}\right )-\frac {\mathrm {erfc}\left (a+b\,x\right )\,\left (\frac {d\,a^2}{2}-b\,c\,a+\frac {d}{4}\right )}{b^2}+\frac {d\,x^2\,\mathrm {erfc}\left (a+b\,x\right )}{2}-\frac {d\,x\,{\mathrm {e}}^{-a^2-2\,a\,b\,x-b^2\,x^2}}{2\,b\,\sqrt {\pi }} \]