Integrate by parts:
int 5^x sinx dx = int 5^x d/dx (-cosx) dx ∫5xsinxdx=∫5xddx(−cosx)dx
int 5^x sinx dx = = -5^xcosx + int cosx d/dx(5^x) dx ∫5xsinxdx==−5xcosx+∫cosxddx(5x)dx
int 5^x sinx dx = = -5^xcosx + ln5 int cosx 5^xdx ∫5xsinxdx==−5xcosx+ln5∫cosx5xdx
and then again:
int 5^x sinx dx = = -5^xcosx + ln5 int d/dx(sinx) 5^xdx ∫5xsinxdx==−5xcosx+ln5∫ddx(sinx)5xdx
int 5^x sinx dx = = -5^xcosx + ln5sinx5^x - ln5 int sinx d/dx( 5^x)dx ∫5xsinxdx==−5xcosx+ln5sinx5x−ln5∫sinxddx(5x)dx
int 5^x sinx dx = = 5^x(ln5sinx- cosx) - ln^2 5 int sinx5^xdx ∫5xsinxdx==5x(ln5sinx−cosx)−ln25∫sinx5xdx
The integral now appears on both sides of the equation and we can solve for it:
(1+ln^2 5)int 5^x sinx dx = 5^x(ln5sinx- cosx)+C(1+ln25)∫5xsinxdx=5x(ln5sinx−cosx)+C
int 5^x sinx dx = (5^x(ln5sinx- cosx))/(1+ln^2 5)+C∫5xsinxdx=5x(ln5sinx−cosx)1+ln25+C