龙虾行天下
幼苗
共回答了15个问题采纳率:80% 举报
1)垂直渐近线:解得使分母为0的点x0,lim(x→x0)f(x)=无穷,x=x0是垂直渐近线,比如y=3x/(x+1),lim(x→-1)[3x/(x+1)]=无穷,x=-1是垂直渐近线.
2)水平渐近线:lim(x→无穷)f(x)=b,y=b是水平渐近线.比如lim(x→无穷)[3x/(x+1)]=3,y=3是水平渐近线.
3)斜渐近线:lim(x→无穷)f(x)/x=a,lim(x→无穷)[3x/(x+1)-ax]=b,y=ax+b是斜渐近线.比如y=(x^2+2x-1)/x,lim(x→无穷)(x^2+2x-1)/x^2=1,lim(x→无穷)[(x^2+2x-1)/x-x]=2,y=x+2是斜渐近线.
1年前
18