0 / | | -a*x | E *cos(b)*x dx | / oo
Integral((E^((-a)*x)*cos(b))*x, (x, oo, 0))
// -a*x \ ||(-cos(b) - a*x*cos(b))*e 2 | / ||---------------------------- for a != 0| | || 2 | | -a*x || a | | E *cos(b)*x dx = C + |< | | || 2 | / || x *cos(b) | || --------- otherwise | || 2 | \\ /
/ -cos(b) pi | -------- for |arg(a)| < -- | 2 2 | a | | 0 < / | | | | -a*x | | x*cos(b)*e dx otherwise | | |/ \oo
=
/ -cos(b) pi | -------- for |arg(a)| < -- | 2 2 | a | | 0 < / | | | | -a*x | | x*cos(b)*e dx otherwise | | |/ \oo
Piecewise((-cos(b)/a^2, Abs(arg(a)) < pi/2), (Integral(x*cos(b)*exp(-a*x), (x, oo, 0)), True))
Estos ejemplos se pueden aplicar para introducción de los límites de integración inferior y superior.