解答题 16.
S0=∫02f(x)e-xdx,S1=∫23f(x-2)e-xdx,…,Sn=∫2n2n+2f(x-2n)e-xdx,求
【正确答案】S0=∫02f(x)e-xdx=∫01xe-xdx+∫12(2-x)e-xdx=(1-)2
令t=x-2,则S1=e-202f(t)e-tdt=e-2S0
令t=x-2n,则Sn=e-2n02f(t)e-tdt=e-2nS0
S=Sn=S0e-2n=
【答案解析】