()d+()dh=2m2rs[/)] 当R→ f(r)e" dx+lim[ f()e"edz 2∑rs/(b)-1l=0 由约旦引理mJ()d=0 若f(x)为偶函数 则2/()k=2nr[(L=0 Ch 5(r)cos prd=Ti2 res [ (bxJe o Im >0当 R ® ¥ ( ) ( ) å [ ( ) ] ò ò + = - k l ipb k c ipz R R ipx k R f x e dx f z e dz i f b e 内 2p res ( ) ( ) ò ò ® ¥ ¥ - ¥ + R c ipz R ipx f x e dx lim f z e dz å [ ( ) ] > = k z ipb k k i f b e Im 0 2p res lim ( ) = 0 ò ® ¥ R c ipz R 由约旦引理 f z e dz ( ) å [ ( ) ] ò > ¥ = k z ipb k k f x pxdx i f b e Im 0 0 则 2 cos 2p res 若 f (x )为偶函数 , ( ) å [ ( ) ] ò > ¥ \ = k z ipb k k f x pxdx i f b e Im 0 0 cos p res