Question

当x→∞时,函数f(x)吁1/x^4是等价无穷小量,函数g(x)与1/x^2是等价无穷小,则则x

∞时，xf(x)/g(x)为多?

Answer 1

f(x)~1/x^4
函数g(x)~1/x^2
lim(x→∞)xf(x)/g(x)=lim(x→∞)(x/x^4)/1/x^2
=lim(x→∞)1/x=0