球面镜像法 。数学描述： 9=- 9=-29 b=a-a 2a 2 a 1 2 92=- 39 91 b= d d 3 a 2 91 9=(-1y96 i+l 6s1*1 a i+2 limq;=0 limb =a i00 i-→00 13 球面镜像法  数学描述： q1 q2 q0 100 1 2 a qqq d =− =− 2 2 2 2 aaa b d a = = = 2 10 1 1 3 a q qq d =− = 2 2 1 2 3 3 2 a a b a d a = = = 0 ( 1) 1 i i q q i = − + 1 2 i i b a i + = + lim 0 i i q →∞ = lim i i b a →∞ = XIDIAN UNIVERSITY LEXU@MAIL.XIDIAN.EDU.CN