## Trigonometry 7th Edition

As the angle $\theta$ increases from $0^o$ to $90^o$, the value of $\cos{\theta}$ tends toward $0$.
From $0^o$ to $90^o$, the value of $\cos{\theta}$ decreases from $1$ to $0$. Thus, as $\theta$ increases from $0^o$ to $90^o$, the value of $cos{\theta}$ approaches $0$.