1.lim(x^2+2x -2)/(x^2+1)=
只要把x=-1代人上面式子即可
所以:lim(x^2+2x -2)/(x^2+1)=(1-2-2)/(1+1)=-3/2
2.lim
x->无穷 (1+1/x)(2-1/x^2)
当x趋向∞时,1/x趋向0.1/x^2趋向0
所以:lim
x->无穷 (1+1/x)(2-1/x^2)=(1+0)(2-0)=2