inte^xsin(4x)dx=-1/4inte^xfrac{d}{dx}(cos(4x))dx
=-1/4[e^xcos(4x)-intfrac{d}{dx}(e^x)cos(4x)dx]
=1/4inte^xcos(4x)dx-1/4e^xcos(4x)
=1/16inte^xfrac{d}{dx}(sin(4x))dx-1/4e^xcos(4x)
=1/16[e^xsin(4x)-intfrac{d}{dx}(e^x)sin(4x)dx]-1/4e^xcos(4x)
=1/16e^xsin(4x)-frac{1}{16}inte^xsin(4x)dx-1/4e^xcos(4x)
frac{17}{16}inte^xsin(4x)dx=1/16e^xsin(4x)-1/4e^xcos(4x)+c_1,
where c_1 is the constant of integration.
inte^xsin(4x)dx=frac{e^xsin(4x)-4e^xcos(4x)}{17}+c_2,
where c_2=frac{16c_1}{17}.