# Math Help - limit

1. ## limit

I need to show that lim[cos(x^2)/x] as x goes to infinity is zero and the limit of its derivative does not exist.

Thx

I need to show that lim[cos(x^2)/x] as x goes to infinity is zero and the limit of its derivative does not exist.

Thx
$-1 \leq \cos x^2 \leq 1$...

As for proving that "the limit of its derivative does not exist", what is the derivative of $$cos(x^2)/x$$?