江画猩工式塑辱院 4.=20204(12 bn=k、 n -=xdx=(1-0sm) 2K 当n=1,3,, 0当n=2,4, k 2K Tx 1 1.3πv1,5πr ∴∫(x)=十i。+sin+sin-。+ T (-00<x<+∞;x≠0,±2,±4,…)江西理工大学理学院 ∫ π ⋅ 20 2 cos 21 xdx n k = 0, ∫ π = ⋅ 20 2 sin 21 xdx n b k n (1− cos π) π = n nk , 0 2,4,6, 1,3,5, 2 ⎪⎩ ⎪⎨⎧ = = = π L L n n n k 当 当 ) 25 sin 51 23 sin 31 2 (sin 2 2 ( ) +L π + π + π π ∴ = + k k x x x f x (−∞ < x < +∞; x ≠ 0,±2,±4,L) an = (n = 1,2,L)