Question:
Write the range of the function $1(x)=\cos [x]$, where $\frac{-\pi}{2}
Solution:
Since $f(x)=\cos [x]$, where $\frac{-\pi}{2} $-\frac{\pi}{2} $\Rightarrow-1.57 $\Rightarrow[x] \in\{-1,0,1,2\}$ Thus, $\cos [x]=\{\cos (-1), \cos 0, \cos 1, \cos 2\}$. Range of $f(x)=\{\cos 1,1, \cos 2\}$.