定理2 若limf(z)= A lim g(z)=B,则 z→>0 im[f(z)±g(z)]=limf(z)土lim(z)=A±B lim f(8(z)=lim f()lim g(z)=AB z→>z0 z→Z f(z) lim f(z) lim z→)20g(z)Iimg(z)2z→z0 (limg(z)≠0B 以上定理用极限定义证  B A g z g z f z g z f z f z g z f z g z AB f z g z f z g z A B f z A g z B z z z z z z z z z z z z z z z z z z z z z z z z =  = = =  =  =  = = → → → → → → → → → → → → (lim ( ) 0) lim ( ) lim ( ) ( ) ( ) lim lim ( ) ( ) lim ( )lim ( ) lim ( ) ( ) lim ( ) lim ( ) lim ( ) lim ( ) , 0 0 0 0 0 0 0 0 0 0 0 0 若 则 定理2  以上定理用极限定义证!