vE>03>0Vx∈(x-8,x)∪(x0,x0+O) →A-E<f(x)<A+E 极限的几何解释 y=f( =A+8 A+8 A-8 y=d-c +6 September. 2004September, 2004    0 0 0 0 0   − + x x x x x ( , ) ( , )    −   + A f x A   ( )    0 极限的几何解释 0 x A y f x = ( ) A+ A− 0 x − 0 x + y A = +  y A = −