Answer
$\lim\limits_{\theta\to0}\dfrac{\cos{\theta}\tan{\theta}}{\theta}=1.$
Work Step by Step
Using Theorem $1.9:$
$\lim\limits_{\theta\to0}\dfrac{\cos{\theta}\tan{\theta}}{\theta}=\lim\limits_{\theta\to0}\dfrac{\cos{\theta}(\dfrac{\sin{\theta}}{\cos{\theta}})}{\theta}=\lim\limits_{\theta\to0}\dfrac{\sin{\theta}}{\theta}=1.$