Answer
As the angle $\theta$ increases from $0^o$ to $90^o$, the value of $\cos{\theta}$ tends toward $0$.
Work Step by Step
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 $0$.