1、_ -2 _- 2_x _Xoh-Xo-hXXoXo ho h _-4 _x x_R R2-2 2 2 _0 03 2 2 _3 2 n n _n=1 n=1000 - - - 0 X XXo X XXo X XXo X XXo X XXo X XXo X XXo X XXo“ (x) (x) (X)(X) (X)-(X) (X)-(X) 1 - 1 3 3 2 23 2n n n n n=1 2 x 33 12 -2-12-1-2-12-1X XXo X XXo 2 - - 3 4 4 4 4- x 2 x0 3 0 x0 22y0 “ “ “ “ “ nnoo nn o n=o n=o n
2、2 D 1. 1 0 x _1. y 0 y _1. x 0 x _1. x 0 x _ - 2- x4/3 - x 2t 1 0 t -_ x x asin 0 0 2 - _ - -22/2 20 0 - - - _ - - - 2- x4/3 2- x-x- x2 x- x x2x-x x x-x x- - - - - - - -_ _x +y + sinz _ x + y + sinz _ asin - 2 3 0 0 0/2 2 3d 2 0 2 2 2 2 2 - - - n n -n n=0 n=0 n -n n n=0 n+1- -kt/m t=0-kt/m _ - - _ 2 _ -
