calculus - Argue $lim_{thetarightarrow 0^+}frac{cosfrac{1}{theta}sintheta-thetacosfrac{1}{theta}}{theta} = 0$

My Teacher wants us to argue that this equation below is true. I am just curious how I would actually explain this? I mean I understand how its true but how can I argue this?

$$\lim_{\theta\rightarrow 0^+}\frac{\cos\frac{1}{\theta}\sin\theta-\theta\cos\frac{1}{\theta}}{\theta} = 0$$