求下列不定积分∫xe^x dx,∫e^xcos2xdx,∫e^2e^dx...

∫xe^x dx,
=∫xde^x
=xe^x-∫e^xdx
=xe^x-e^x+c
∫e^xcos2xdx
=(1/2)∫e^xdsin2x
=(1/2)e^xsin2x-(1/2)∫sin2xe^xdx
=(1/2)e^xsin2x+(1/4)∫e^xdcos2x
=(1/2)e^xsin2x+(1/4)e^xcos2x-(1/4)∫cos2xe^xdx
所以：
本题=（2/5）e^xsin2x+(1/5)e^xcos2x+c.
第三题题目不完整.
∫e^2e^dx