\(\int \Gamma (0,a x) \, dx\) [4]

Optimal result

Integrand size = 5, antiderivative size = 19 \[ \int \Gamma (0,a x) \, dx=-\frac {e^{-a x}}{a}+x \Gamma (0,a x) \] Output:

-1/a/exp(a*x)+x*Ei(1,a*x)
 

Mathematica [A] (verified)

Time = 0.01 (sec) , antiderivative size = 19, normalized size of antiderivative = 1.00 \[ \int \Gamma (0,a x) \, dx=-\frac {e^{-a x}}{a}+x \Gamma (0,a x) \] Input:

Integrate[Gamma[0, a*x],x]
 

Output:

-(1/(a*E^(a*x))) + x*Gamma[0, a*x]
 

Rubi [A] (verified)

Time = 0.16 (sec) , antiderivative size = 19, normalized size of antiderivative = 1.00, number of steps used = 1, number of rules used = 1, \(\frac {\text {number of rules}}{\text {integrand size}}\) = 0.200, Rules used = {7111}

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.

\(\displaystyle \int \Gamma (0,a x) \, dx\)

\(\Big \downarrow \) 7111

\(\displaystyle x \Gamma (0,a x)-\frac {e^{-a x}}{a}\)

Input:

Int[Gamma[0, a*x],x]
 

Output:

-(1/(a*E^(a*x))) + x*Gamma[0, a*x]
 

Defintions of rubi rules used

rule 7111

Int[Gamma[n_, (a_.) + (b_.)*(x_)], x_Symbol] :> Simp[(a + b*x)*(Gamma[n, a 
+ b*x]/b), x] - Simp[Gamma[n + 1, a + b*x]/b, x] /; FreeQ[{a, b, n}, x]
 

Maple [A] (verified)

Time = 0.29 (sec) , antiderivative size = 19, normalized size of antiderivative = 1.00

method	result	size
parts	\(x \,\operatorname {expIntegral}_{1}\left (x a \right )-\frac {{\mathrm e}^{-x a}}{a}\)	\(19\)
derivativedivides	\(\frac {x a \,\operatorname {expIntegral}_{1}\left (x a \right )-{\mathrm e}^{-x a}}{a}\)	\(21\)
default	\(\frac {x a \,\operatorname {expIntegral}_{1}\left (x a \right )-{\mathrm e}^{-x a}}{a}\)	\(21\)
parallelrisch	\(\frac {x a \,\operatorname {expIntegral}_{1}\left (x a \right )-{\mathrm e}^{-x a}}{a}\)	\(21\)
meijerg	\(\frac {-\left (\gamma -1+\ln \left (x \right )+\ln \left (a \right )\right ) x a -x a +1-{\mathrm e}^{-x a}-a x \left (-\gamma -\ln \left (x a \right )-\operatorname {expIntegral}_{1}\left (x a \right )\right )}{a}\)	\(50\)

Input:

int(Ei(1,x*a),x,method=_RETURNVERBOSE)
 

Output:

x*Ei(1,x*a)-exp(-x*a)/a
 

Fricas [F(-2)]

Exception generated. \[ \int \Gamma (0,a x) \, dx=\text {Exception raised: TypeError} \] Input:

integrate(exp_integral_e(1,a*x),x, algorithm="fricas")
 

Output:

Exception raised: TypeError >> An error occurred when FriCAS evaluated exp 
_integral_e(((1)::EXPR INT),(a)*(x)):   There are no library operations na 
med exp_integral_e       Use HyperDoc Browse or issue
 

Sympy [A] (verification not implemented)

Time = 0.17 (sec) , antiderivative size = 19, normalized size of antiderivative = 1.00 \[ \int \Gamma (0,a x) \, dx=\begin {cases} x \operatorname {E}_{1}\left (a x\right ) - \frac {e^{- a x}}{a} & \text {for}\: a \neq 0 \\x \operatorname {E}_{1}\left (0\right ) & \text {otherwise} \end {cases} \] Input:

integrate(expint(1,a*x),x)
 

Output:

Piecewise((x*expint(1, a*x) - exp(-a*x)/a, Ne(a, 0)), (x*expint(1, 0), Tru 
e))
 

Maxima [A] (verification not implemented)

Time = 0.03 (sec) , antiderivative size = 10, normalized size of antiderivative = 0.53 \[ \int \Gamma (0,a x) \, dx=-\frac {E_{2}\left (a x\right )}{a} \] Input:

integrate(exp_integral_e(1,a*x),x, algorithm="maxima")
 

Output:

-exp_integral_e(2, a*x)/a
 

Giac [F]

\[ \int \Gamma (0,a x) \, dx=\int { E_{1}\left (a x\right ) \,d x } \] Input:

integrate(exp_integral_e(1,a*x),x, algorithm="giac")
 

Output:

integrate(exp_integral_e(1, a*x), x)
 

Mupad [B] (verification not implemented)

Time = 0.05 (sec) , antiderivative size = 17, normalized size of antiderivative = 0.89 \[ \int \Gamma (0,a x) \, dx=x\,\mathrm {expint}\left (a\,x\right )-\frac {{\mathrm {e}}^{-a\,x}}{a} \] Input:

int(expint(a*x),x)
 

Output:

x*expint(a*x) - exp(-a*x)/a
 

Reduce [F]

\[ \int \Gamma (0,a x) \, dx=\int \mathit {ei} \left (1, a x \right )d x \] Input:

int(Ei(1,a*x),x)
 

Output:

int(ei(1,a*x),x)