用分部积分法做
∫ xe^4x dx (u = x,v' = e^4x,v = 1/4 e^4x)
= (1/4)xe^4x - (1/4) ∫ e^4x dx
= (1/4)xe^4x - (1/4)(1/4) e^4x + C
= (1/4)xe^4x - (1/16)e^4x + C
xe^4xdx用不定积分求解
用分部积分法做
∫ xe^4x dx (u = x,v' = e^4x,v = 1/4 e^4x)
= (1/4)xe^4x - (1/4) ∫ e^4x dx
= (1/4)xe^4x - (1/4)(1/4) e^4x + C
= (1/4)xe^4x - (1/16)e^4x + C