⑩天掌 Teaching Plan on Advanced Mathematics o k cos xdx=o, (n 0 n k k. sin-xdx=( 1-cosn兀) 2 n 2k 当n=1,3,5, n几 0￥n=2,4,6, k2k.,πv 3πx1 STX .f(r) 2+元 (sin-+sin+in+…) 23 2 52 (-∞0<x<+;x≠0,+2,+4,) tianjin polytechnic dmivendityTianjin Polytechnic University Teaching Plan on Advanced Mathematics    2 0 2 cos 2 1 xdx n k = 0,   =  2 0 2 sin 2 1 xdx n bn k (1− cos )  = n n k , 0 2,4,6, 1,3,5, 2      = = =    n n n k 当 当 ) 2 5 sin 5 1 2 3 sin 3 1 2 (sin 2 2 ( ) +  +  +    = + k k x x x f x (−  x  +; x  0,2,4, ) an = (n = 1,2, )