Question

正无穷lim(x^2+x)sin1/x

Answer 1

x->正无穷 lim(sin1/x) /(1/x) =y->0 lim siny/y =1 (令y=1/x)

所以x->正无穷 lim(x^2+x)sin1/x =lim (x^2+x)* 1/x =lim(x+1 ) =+∞