Question

请问这题极限怎么求

Answer 1

原式=1，过程如图，

Answer 2

(2)
lim(x->4) (x^2-6x+8)/(x^2-5x+4)
=lim(x->4) (x-4)(x-2)/[(x-1)(x-4)]
=lim(x->4) (x-2)/(x-1)
=(4-2)/(4-1)
=2/3
(6)
lim(x->+∞) √(x^2-x)/(x+4)

分子分母同时除以x
=lim(x->+∞) √(1-1/x)/(1+4/x)
=1