Evaluating Limits I am having trouble understanding this question on limits. Suppose that $r(x)$ is a function where 
$$
\lim_{x\rightarrow 0} \dfrac{r(x)}{x^2} =0 \ .
$$   
Can someone please explain how, from the first limit I can show that: 
$$
\lim_{x\rightarrow 0} \dfrac{r(x)}{x} =0 \ . 
$$

Since 
$$\lim_{x\rightarrow 0}\frac{r(x)}{x^{2}}=\lim_{x\rightarrow 0}\frac{%
r(x)}{x}\cdot \lim_{x\rightarrow 0}\frac{1}{x}=0$$
and 
$$\lim_{x\rightarrow 0}\frac{1}{x}\neq 0,$$
we must have
$$\lim_{x\rightarrow 0}\frac{r(x)}{x}=0.$$
