How do I find the limit as xx approaches infinity of xsin(1/x)xsin(1x)?

1 Answer
Sep 26, 2014

By l'Hopital's Rule,

lim_{x to infty}x sin(1/x)=1

Let us look at some details.

lim_{x to infty}x sin(1/x)

by rewriting a bit,

=lim_{x to infty}{sin(1/x)}/{1/x}

by l'Hopital's Rule,

=lim_{x to infty}{cos(1/x)cdot(-1/x^2)}/{-1/x^2}

by cancelling out -1/x^2,

=lim_{x to infty}cos(1/x)=cos(0)=1