[(2+e的x分之1)/(1+e的x分之2)+ |x|/x]在x趨向於0時的極限

[(2+e的x分之1)/(1+e的x分之2)+ |x|/x]在x趨向於0時的極限

(x->0)lim[2+e^(1/x)]/[(1+e^(2/x)] + |x|/x
=(t->∞)lim(2+e^t)/(1+e^2t)+ t/|t|變換變數t=1/x
=(t->∞)lim(2/e^t+1)/(1/e^t+e^t)+ t/|t|
=(t->∞)lim 1/e^t + t/|t|
=(t->∞)lim t/|t|
t->+∞,原式=1
t->-∞,原式=-1
故原式不存在極限