(2)求余弦级数对f(x)进行奇延拓 2 a、2r4(x+1)dk=兀+2, (x+1)cosnxdx 元0 元 n=2 999 (cos nT-1)= 4 nt元 n=1,35 n兀 +I兀 +1--(c0x+,2C0s3x+2C0s5x+ 2 3 5 (0≤x≤π) 上一页下一页返回=  +   0 0 ( 1) 2 a x dx =  + 2, =  +   0 ( 1)cos 2 an x nxdx (cos 1) 2 2 =  −  n n      − = = =   , 1,3,5, 4 0, 2,4,6, 2 n n n  cos5 ] 5 1 cos 3 3 1 (cos 4 1 2 1 + 2 + 2 +  + −  x + = x x x (0  x  ) (2)求余弦级数 对 f (x) 进行奇延拓 −  1 o x y