⑩天掌 Teaching Plan on Advanced Mathematics o 将求得的系数带入,就得到∫(x)的傅里叶级数展开式 ∫(x)=-|sinx+sin3x+…+ 2k-tsi(2k-1)x+… (-∞<x<+∞x≠0,土丌,2兀,… tianjin polytechnic dmivendityTianjin Polytechnic University Teaching Plan on Advanced Mathematics 将求得的系数带入，就得到 f ( x) 的傅里叶级数展开式 sin(2 1) ] 2 1 1 sin3 3 1 [sin 4 ( )  − + − = + + + k x k f x x x  (−   x  + ; x  0, ,2 , )