(4)"取极限” 定义△o,的直径为 (Ao,)=mx{P☑R∈△o,} 令2=max{2(Ao,)} ≤i≤n z=f(x,y) V=m∑f5n,)Ao λ→0 f(5,7 i=1 (5,7,) △O1 BEIJING UNIVERSITY OF POSTS AND TELECOMMUNICATIONS PRESS 目录上页下页返回结束目录 上页 下页 返回 结束 (4)“取极限” ( i ) = max P1 P2 P1 ,P2  i  令 max ( )  1 i i n  =     = → =  n i i i i V f 1 0 lim ( , )   ( , ) i i f    i ( , ) i i