Question

求极限Lim x→1 (x^2-2x+1)/(x^2+1)

Answer 1

分子是0，而分母不是0
因此直接把x=1代入得极限是0

Answer 2

(x²-2x+1)/(x²-1)
=(x-1)²/(x+1)(x-1)
=(x-1)/(x+1)
所以极限=(1-1)/(1+1)=0