t算1e,n=0,2 由高等数学知识可知: I,=e[x'e'dx=e"[e'dx=e(e-1)=1-ex0.6321 L.=e-fx'd(e")=e"("e-Le'd(x"))-1-nl. 1.-e恤ex e 1e"ase小r n+1 大致趋势:n越大,I,越小, 0 1 2 . 1 1 0 x e dx n , , , e I n x n = = 计算: 由高等数学知识可知: ( 1) 1 0.6321 1 1 1 0 1 1 0 1 0 0 = = = − = − − − − − I e x e dx e e dx e e e x x ( ) 1 1 0 1 0 1 1 0 1 ( ) ( ) 1 − − − = = − = − n n x n x x n I n e x d e e x e e d x nI 1 1 1 1 1 (max ) 1 (min ) 1 1 0 1 0 1 1 0 1 0 1 1 + + + = + = − − − − n I n e n I e e x dx n e I e e x dx n x n x n x n x n 大致趋势: n 越大, I n 越小