cos(xsing)=.(+()comp+()cosm =()+空.（(ewm9+2.（wm =J(x)+(x)cosmp+"J(xcosm =,()+2[1+(-y旷.()csmp =,()+22J()cs2me m=1 将等式左边展成傅立叶级数，比较系数得： (x)cos(xsinp)cos2mod (=0.1.2.). 偶数阶贝塞耳函数的积分表达式 19 ( ) ( ) ( ) ( ) 0 1 1 cos sin cos cos m m m m x J x J x m J x m     − = =− = + +   ( ) ( ) ( ) 0 1 1 cos cos m m m m J x J x m J x m     − = = = + +   ( ) ( ) ( ) ( ) 0 1 1 cos cos m m m m m J x J x m J x m     = = = + + −   ( ) ( ) ( ) 0 1 1 1 cos m m m J x J x m  = = + + −     ( ) ( ) 0 2 1 2 cos2 m m J x J x m  = = +  将等式左边展成傅立叶级数，比较系数得： ( ) ( ) ( ) 2 0 1 cos sin cos2 0,1,2, . m J x x m d m      = =  ——偶数阶贝塞耳函数的积分表达式