GIF89a.,.ڋ޼HfM ) > 8LАFiKtҚXݸNyau!y{Kg/znMuޚPsؠ34u b'y,[ޭ{~ Uwuz}hMna~M! MathType001 `DSph= Tn `- T(R 2  r -2r 2 ) n 2 R 4  r -4R 2  r r 2 +4r 4;