① lim[x->a] f(x) = lim[t->0] f(t+a) = lim[x->0] f(x+a) = f(a)
由函数在某点连续的定义知,f(x)在a处是连续的.
② 如果f(x)在a处连续,则lim[x->a] f(x) = f(a)
而lim[x->0] f(x+a) = lim[x->a] f(x),所以lim [x->0] f(x+a)=f(a)
① lim[x->a] f(x) = lim[t->0] f(t+a) = lim[x->0] f(x+a) = f(a)
由函数在某点连续的定义知,f(x)在a处是连续的.
② 如果f(x)在a处连续,则lim[x->a] f(x) = f(a)
而lim[x->0] f(x+a) = lim[x->a] f(x),所以lim [x->0] f(x+a)=f(a)