x.y都趋于正无穷大时:lim(x^2+y^2)e^-(x+y)?
问题描述:
x.y都趋于正无穷大时:lim(x^2+y^2)e^-(x+y)?
答
lim(x^2+y^2)e^-(x+y)=lim(x^2/e^x)*lim(1/e^y)+lim(y^2/e^y)*lim(1/e^x)=0
x.y都趋于正无穷大时,前后极限都等于0